Recent interest in large displays has led to the development of a variety of multi-screen display systems, most of which are comprised of multiple projectors situated for front or rear projection onto a screen to form a large logical display, and each projector is driven by one PC, augmented with high-performance graphics accelerator card. However, most of these systems are immediate-mode based, that is, all geometry data and control information must be sent on the run, and thus the interconnecting network bandwidth between clients and servers has become a fatal bottleneck. In this paper, we describe MSPR, a retained-mode based multi-screen parallel rendering system which offers the programmers with a OpenGL-like API. And the system could be run locally on one PF or parallelly rendered among any number of Computers. The details of data distribution, load balance, interconnecting network architecture, tile mosaic, etc. are hidden from the programmers.