!Ref KeyName InstanceType: !Ref InstanceType SecurityGroups: - !Ref Ec2SecurityGroup BlockDeviceMappings: - DeviceName: /dev/sda1 Ebs: VolumeSize: 50 - DeviceName: /dev/sdm Ebs: VolumeSize: 100 MyDB: Type: AWS::RDS::DBInstance Properties: DBSecurityGroups: - Ref: MyDbSecurityByEC2SecurityGroup - Ref: MyDbSecurityByCIDRIPGroup AllocatedStorage: '5' DBInstanceClass: db.t2.small Engine: MySQL MasterUsername: MyName ManageMasterUserPassword: true MasterUserSecret: KmsKeyId: !Ref KMSKey DeletionPolicy: Snapshot CFnはリソースごとにプロパティの書き⽅がまちまち 似て⾮なる記述が多いので、質問の精度が低いと答え を出しきれないのだろう