In this research we use the algebraic method to solve the Economic Production Quantity(EPQ) model with stochastic lead time. Chang (2004) tried to use algebraic method instead of calculus to solve the EPQ model with shortages and probabilistic lead time. Ronald et al. (2004) also tried to improve the algebraic method proposed by Grubbstrom and Erdem (1999) and Cardenas-Barron (2001). The purpose of this research is threefold. First, we clearly explain the methods of Grubbstrom and Erdem, Cardenas-Barron and Chang. Second, we offer an easier and clearer algebraic method to solve the inventory model with stochastic lead time such that extends the algebraic method to a more general problem. Third, our improved method can also solve the inventory models in Ronald et al. (2004) and avoid their complicated procedure.