Grid　cells　in　the　MEC　(media　entorhinal　cortex)　of　rats　show　repetitive　hexagon　firing　pattern　while　moving　through　the　environment.　In　the　deeper　layer　of　the　MEC,　a　kind　of　interneurons　have　both　the　head-directing　(HD)　and　grid-like　firing　properties.　The　predecessors＇　observations　indicate　the　grid　cells　have　ubiquitous　intracellular　rhythmic　oscillating.　Moreover,　the　grid　cells＇　firing　frequencies　have　interesting　approximate　proportion　relationship　with　the　animal＇s　moving　velocity.　However,　animal＇s　perception　of　the　motor　speed　might　be　affected　by　many　other　factors　such　as　visual　signals　or　external　information.　The　oscillation　interference　process　inevitably　follows　with　error　accumulating.　Based　on　what　we　have　mentioned　above,　we　put　forward　an　improved　grid　cell　model　that　handle　speed　signal　in　a　plausible　way　and　ameliorate　the　effects　of　phase　noise.　And　this　paper＇s　model　is　achieved　by　combining　two　prevailing　theories　together　which　might　be　closer　to　the　scientific　truth　of　grid　cells.