According to the survey of the rabbit industrialization base in Dechang county，based on parameter syntax to the rabbit of different species and ages，the paper proved that there are close relationship among body size， chest circumference，ear width and weight. with time goes by，there is a decline in closeness，the direct determination coefficients of half-age group are：dyx1=0.3696，dyx2=0.3934，dyx3=0.3769，dyx4=80.437. the multiple determination coefficients are Σ d=0.8897. To build“the best”regression equation is meaningful to front-line production.