diff --git a/.changelog/11284.txt b/.changelog/11284.txt
new file mode 100644
index 00000000000..da2ba1267f8
--- /dev/null
+++ b/.changelog/11284.txt
@@ -0,0 +1,3 @@
+```release-note:bug
+bigquery: fixed a permadiff when handling "assets" params in the `google_bigquery_data_transfer_config` resource
+```
\ No newline at end of file
diff --git a/google/services/bigquerydatatransfer/resource_bigquery_data_transfer_config.go b/google/services/bigquerydatatransfer/resource_bigquery_data_transfer_config.go
index 6555d8db8ce..aa89ba21601 100644
--- a/google/services/bigquerydatatransfer/resource_bigquery_data_transfer_config.go
+++ b/google/services/bigquerydatatransfer/resource_bigquery_data_transfer_config.go
@@ -1008,6 +1008,19 @@ func resourceBigqueryDataTransferConfigDecoder(d *schema.ResourceData, meta inte
 				}
 			}
 		}
+		for k, v := range params {
+			switch v.(type) {
+			case []interface{}, map[string]interface{}:
+				value, err := json.Marshal(v)
+				if err != nil {
+					return nil, err
+				}
+				params[k] = string(value)
+			default:
+				params[k] = v
+			}
+		}
+		res["params"] = params
 	}
 
 	return res, nil
diff --git a/google/services/bigquerydatatransfer/resource_bigquery_data_transfer_config_test.go b/google/services/bigquerydatatransfer/resource_bigquery_data_transfer_config_test.go
index 726df2bf85e..ccdf9bdf5b1 100644
--- a/google/services/bigquerydatatransfer/resource_bigquery_data_transfer_config_test.go
+++ b/google/services/bigquerydatatransfer/resource_bigquery_data_transfer_config_test.go
@@ -856,7 +856,7 @@ resource "google_bigquery_data_transfer_config" "salesforce_config" {
     "connector.authentication.username"           = ""
     "connector.authentication.password"           = ""
     "connector.authentication.securityToken"      = ""
-    "assets"                                      = "[asset-a, asset-b]"
+    "assets"                                      = "[\"asset-a\",\"asset-b\"]"
   }
 }
 `, randomSuffix, randomSuffix)
diff --git a/website/docs/r/bigquery_data_transfer_config.html.markdown b/website/docs/r/bigquery_data_transfer_config.html.markdown
index 5a245d818da..fa35a001136 100644
--- a/website/docs/r/bigquery_data_transfer_config.html.markdown
+++ b/website/docs/r/bigquery_data_transfer_config.html.markdown
@@ -94,7 +94,7 @@ resource "google_bigquery_data_transfer_config" "salesforce_config" {
     "connector.authentication.username"           = "username"
     "connector.authentication.password"           = "password"
     "connector.authentication.securityToken"      = "security-token"
-    "assets"                                      = "[asset-a, asset-b]"
+    "assets"                                      = "[\"asset-a\",\"asset-b\"]"
   }
 }
 ```