Abstract: In this papar,a direct method far calculating divergence,vorticity and vertical velocity on computer,without objective analysis,is proposed.Similar technique is applicable to calculation of physical quantities,such as gradient,advection and flux.However,in practical application,there still remain some problems to be solved,such as the inconsistency between the number of the vertical boundary conditions usually specified in an atmospheric model and the order of the equation of continuity,the problem how to calculate the vertical velocity in the case of uneven vertical resolution and the case of mountainous regions.To tackle these problems,same preliminary methods have been suggested and the equivalency of two different formulations of vertical velocity has been discussed.The formulations are as follows.