Credit derivatives are rapidly growing in volumes over the global market. These instruments provide a solution to manage the credit risk and increase the liquidity of trading in credit risk. Equity default swap (EDS) is one of the credit derivatives which was first introduced in America in 2004. This paper introduces a pricing method for equity default swap. By Merton (1974) model, we consider EDS as a kind of credit derivatives. Moreover, a maximum-likelihood estimation method is applied to estimate the parameters required for pricing. The problem of unobservable firm asset value data is overcome by a method introduced by Duan (1994) and the technique of changing variables. This paper calculates the EDS spreads with some reference firms. Some of the factors which may affect EDS spread are analyzed. The EDS spreads are sensitive to the stock price data we selected for estimation.