This paper investigates a two-echolon inventory system with （S-1，S） policy that consists of several same repairable items and single repair facility， and assumes that the item demand occur according to a markovian arrival process （MAP）， the repair time， ship time and procurement time follow the general distribution which is represented by phase-type （PH） distribution. Then a inventory optimization model with better description ability and analytical performance is given， and the probability distribution of backorder is obtained. Finally， a numerical example was given to illustrate the effectiveness of the model.