Yes, on-site inspections are often necessary for NMPA registration of medical devices in China, particularly for Class II and Class III devices. The NMPA conducts these inspections to:

1. Verify Compliance: Ensure that the manufacturing facility meets the required quality management standards, such as ISO 13485.
2. Assess Production Processes: Evaluate the production processes and quality control measures in place.
3. Confirm Device Safety and Efficacy: Verify that the device's design and manufacturing processes align with the submitted documentation and comply with safety and performance standards.

For Class I devices, the requirement for an on-site inspection may be less stringent, but it can still occur depending on the device type and risk level.

If you're preparing for NMPA registration, ensuring your facility is audit-ready and adheres to relevant standards will help facilitate the process. If you have any more specific questions or need further guidance, just let me know!