The update transactions to be executed in spatial databases have been usually known as interactive and long duration works. When a spatial object has a very large geometry of which size is larger than the screen window, it needs to concurrently update such a large spatial object for improving concurrency of updating spatial objects. Under the existing locking protocols, it is not allowed a large spatial object to be concurrently updated. We propose a partial locking scheme of allowing a transaction to set locks on parts of the large object. The partial locking scheme acquires a lock for part of the large object to allow several users to concurrently update the same object. The scheme gives benefits of improving the concurrency of updating a large object while maintaining the consistency of long duration transactions for interactively updating spatial data.