This paper provided a measure to estimate the meat yield and to selective breed of Procambarus clarkii and Cherax quadricarinatus. The correlation between meat yield and body measurements in these two kinds of crayfish were studied by statistics analysis. The results showed that, the meat yield value of Cherax quadricarinatus was higher than that of Procambarus clarkii. First abdominal segment width was the main variable to Procambarus clarkii. Body length and carapace length were the main variables to Cherax quadricarinatus, followed by total length. It was concluded that: (1) the correlation to meat yield was more significant than that to body weight; (2) it was possible to predicting meat yield based on ratio of two body measurements or the individual variable in Procambarus clarkii and Cherax quadricarinatus.