As an important computer graphics technique, parameter-driven animation has seen increasing deployment on mobile platforms, where both communication bandwidth and device storage are subjected to stringent constraints. We propose an efficient rate-distortion optimized inter-frame compression scheme for parameter-driven animation capable of finding optimal bit-allocations for any given bit-rate. Experiments conducted on face animation based on active appearance models demonstrate that with the proposed method, the transmission and storage requirements of parameter-driven animation can be significantly reduced.