diff --git a/backend/apps/fields/urls.py b/backend/apps/fields/urls.py
new file mode 100644
index 0000000..1b0bc3f
--- /dev/null
+++ b/backend/apps/fields/urls.py
@@ -0,0 +1,7 @@
+from django.urls import path
+from . import views
+
+urlpatterns = [
+    path('import/kyosai/', views.import_kyosai_master, name='import_kyosai'),
+    path('import/yoshida/', views.import_yoshida_fields, name='import_yoshida'),
+]
diff --git a/backend/apps/fields/views.py b/backend/apps/fields/views.py
index 91ea44a..a4379bd 100644
--- a/backend/apps/fields/views.py
+++ b/backend/apps/fields/views.py
@@ -1,3 +1,133 @@
-from django.shortcuts import render
+import pandas as pd
+from django.http import JsonResponse
+from django.views.decorators.csrf import csrf_exempt
+from django.views.decorators.http import require_http_methods
+from .models import OfficialKyosaiField, OfficialChusankanField, Field
 
-# Create your views here.
+
+@csrf_exempt
+@require_http_methods(["POST"])
+def import_kyosai_master(request):
+    if 'file' not in request.FILES:
+        return JsonResponse({'error': 'No file uploaded'}, status=400)
+
+    ods_file = request.FILES['file']
+
+    try:
+        df = pd.read_excel(ods_file, engine='odf')
+        
+        created_count = 0
+        updated_count = 0
+
+        for _, row in df.iterrows():
+            k_num = str(row.get('k_num', '')).strip() if pd.notna(row.get('k_num')) else ''
+            s_num = str(row.get('s_num', '')).strip() if pd.notna(row.get('s_num')) else ''
+            
+            if not k_num:
+                continue
+
+            defaults = {
+                's_num': s_num,
+                'address': str(row.get('address', '')).strip() if pd.notna(row.get('address')) else '',
+                'kanji_name': str(row.get('kanji_name', '')).strip() if pd.notna(row.get('kanji_name')) else '',
+                'area': float(row.get('area', 0)) if pd.notna(row.get('area')) else 0,
+            }
+
+            obj, created = OfficialKyosaiField.objects.update_or_create(
+                k_num=k_num,
+                defaults=defaults
+            )
+
+            if created:
+                created_count += 1
+            else:
+                updated_count += 1
+
+        return JsonResponse({
+            'success': True,
+            'created': created_count,
+            'updated': updated_count,
+            'message': f'共済マスタ: {created_count}件作成, {updated_count}件更新'
+        })
+
+    except Exception as e:
+        return JsonResponse({'error': str(e)}, status=500)
+
+
+@csrf_exempt
+@require_http_methods(["POST"])
+def import_yoshida_fields(request):
+    if 'file' not in request.FILES:
+        return JsonResponse({'error': 'No file uploaded'}, status=400)
+
+    ods_file = request.FILES['file']
+
+    try:
+        df = pd.read_excel(ods_file, engine='odf')
+        
+        created_count = 0
+        updated_count = 0
+
+        for _, row in df.iterrows():
+            name = str(row.get('name', '')).strip() if pd.notna(row.get('name')) else ''
+            
+            if not name:
+                continue
+
+            raw_kyosai_k = str(int(row.get('raw_kyosai_k_num', 0))) if pd.notna(row.get('raw_kyosai_k_num')) else None
+            raw_kyosai_s = str(int(row.get('raw_kyosai_s_num', 0))) if pd.notna(row.get('raw_kyosai_s_num')) else None
+            raw_chusankan = str(int(row.get('raw_chusankan_id', 0))) if pd.notna(row.get('raw_chusankan_id')) else None
+
+            area_tan = float(row.get('area_tan', 0)) if pd.notna(row.get('area_tan')) else 0
+            area_m2 = int(row.get('area_m2', 0)) if pd.notna(row.get('area_m2')) else 0
+
+            defaults = {
+                'address': str(row.get('address', '')).strip() if pd.notna(row.get('address')) else '',
+                'area_tan': area_tan,
+                'area_m2': area_m2,
+                'owner_name': str(row.get('owner_name', '')).strip() if pd.notna(row.get('owner_name')) else '',
+                'raw_kyosai_k_num': raw_kyosai_k,
+                'raw_kyosai_s_num': raw_kyosai_s,
+                'raw_chusankan_id': raw_chusankan,
+            }
+
+            field, created = Field.objects.update_or_create(
+                name=name,
+                defaults=defaults
+            )
+
+            if created:
+                created_count += 1
+            else:
+                updated_count += 1
+
+            if raw_kyosai_k:
+                try:
+                    kyosai_record = OfficialKyosaiField.objects.get(k_num=raw_kyosai_k)
+                    field.kyosai_fields.add(kyosai_record)
+                except OfficialKyosaiField.DoesNotExist:
+                    pass
+
+            if raw_kyosai_s:
+                try:
+                    kyosai_record = OfficialKyosaiField.objects.get(s_num=raw_kyosai_s)
+                    field.kyosai_fields.add(kyosai_record)
+                except OfficialKyosaiField.DoesNotExist:
+                    pass
+
+            if raw_chusankan:
+                try:
+                    chusankan_record = OfficialChusakanField.objects.get(c_id=raw_chusankan)
+                    field.chusankan_fields.add(chusankan_record)
+                except OfficialChusankanField.DoesNotExist:
+                    pass
+
+        return JsonResponse({
+            'success': True,
+            'created': created_count,
+            'updated': updated_count,
+            'message': f'実圃場: {created_count}件作成, {updated_count}件更新'
+        })
+
+    except Exception as e:
+        return JsonResponse({'error': str(e)}, status=500)
diff --git a/backend/keinasystem/urls.py b/backend/keinasystem/urls.py
index 9f99a94..5e161fa 100644
--- a/backend/keinasystem/urls.py
+++ b/backend/keinasystem/urls.py
@@ -15,8 +15,9 @@ Including another URLconf
     2. Add a URL to urlpatterns:  path('blog/', include('blog.urls'))
 """
 from django.contrib import admin
-from django.urls import path
+from django.urls import path, include
 
 urlpatterns = [
     path('admin/', admin.site.urls),
+    path('api/fields/', include('apps.fields.urls')),
 ]