Abstract: Based on the price-volume relation, the paper explains the distribution of the rate of return using the distribution of volume.We respectively discuss the relationship between the expected volume and the rate of return, and the unexpected volume and the rate of return.It is found that there is a significant positive correlation between the trading volume and the rate of returns, and that the rate of return can explain the effect on expected trading volume and unexpected trading volume, and either expected trading volume or unexpected trading volume can explain the effect on the rate of return.The volume in the data shows no obvious effect on the rate of return, but from the statistical characteristics, the distribution of the former can explain the distribution of the latter.