The cooperation strategy followed by the buyer and vendor results is an overall effect on the saving percentage along with the impact of inventory costs such as holding cost, fixed and linear backorder cost. This paper deals with buyer - vendor incentive inventory model with fixed lifetime product with fixed and linear back order cost. A distinguishing feature of this model is that both fixed and linear backorder costs are included, where as previous work include without backorders. The model is developed and proved with a numerical example. The outcome of increasing holding cost, backorder cost for both buyer and vendor or individually is found.