Abstract: Four traditional VRS stochastic modeling methods and the VENUS method proposed by the authors were given.Comparison of these methods from different aspects,including posterior variances,ADOP,F-ration,filtered residual were comprehensively analyzed.Test results show that the effectiveness of the Standard,SNR and the Elevation-dependent stochastic modeling methods are not very ideal.Meanwhile,both the Adapt and the VENUS method take on their own advantages and disadvantages.Hence,it is advisable to integrate all of these advantages into one new method.