Abstract:Considering the negative correlation of stock returns and its volatility,this paper established a timevarying infinite pure jump Levy processes with time-changed conditional expectations and volatility in discretetime.According to local martingale measure transformation,we derived its equivalent risk neutral pricing model for the conditional Levy processes and used in the Hang Seng Index options for empirical research.Studies show: the conditional Levy processes with leverage effect jointly portray the asset prices’time-varying drift, variance,non-Gauss random innovations and asymmetric volatility four states,and this model has wide applicability; compared to Brownian Motion,Jump-Diffusion,and Variance Gamma process,Tempered Stable models have better performance in capturing leptokurtosis and fat-tailed features; with leverage effect,option pricing capacity of conditional Levy process has been greatly improved,we also found that Rapidly Decreasing Tempered Stable process performs more robust.