A sensitivity analysis by the graph of expected unit-profit function for a N-stage Series-Type Inventory Model is discussed.At first, the sensitivity analysis of the optimal stock level and the expected profit against the change of the parameters of demand distribution is analyzed.Next, by the graph of expected unit-profit funciton at each stage, how the change of the parameters (backorder-rations, cost of ordering, holding stocks, transportation, liquidation loss and opportunity loss) has influence on the stock point is examined.Firnally, by this graph, the relationship between expected profit and holding capacity constraints is discussed.