In this paper, the effects of collision on the dispersion equation of plasma are discussed under two kinds of collision models (BGK model and LB model). Analysis shows that the main effect of collision is to change the usual dispersion function Z(ξ) into a generalized one W(ξ,ν). The properties of W function have been analysed and compared for two models. The effects of collision on low frequeny drift wave (local mode) and ion-acoustic wave have been discussed. It is shown that LB model is not only more reasonable physically than BGK model, but also more simple in calculation and expression.