Abstract: By applying WKBJ method to a linearized Boussinesq system of two dimensions in the Y-Z plane, a generalized conservative wave action density of the gravity waves in a nonuniformly stratified fluid with shearing basic current was derived. And the effects of the nonuniform structures (e. g. jet type patterns) of the basic current on the development of the gravity waves were stressed based on the development equation of the gravity waves obtained from the wave action conservation principle.The results showed that the jet type structure in basic current favors the development of the gravity waves propagting horizontally towards the right hand side of the jet (facing downstream of the jet).