This article has structured the stock cost models of retail dealer and supplier under the time-variable demand.It pointed that the lacking goods time-points of retail dealer not only affected itself also did affect the cost achievements of supplier and the supply chain.It has optimized the lacking goods time-points of retail dealer form the overall angle based on the partial optimization of the retail dealer lacking goods time-points and the supplier satisfied batch of ordering goods.At last,it structured a coordinated mechanism,called cost sharing,to guarantee the optimized situation.