Selected hybridoma which secreted steadily anti-human liver McAb were injected a variant sex and age LOU/C-Igk-1b rat to obtain the ascites. The data suggest th e output of the ascites is the peak in 20 weeks and have no significant differe nce in sex. It indicates that the output of the ascites from 3A5 McAb is correla t ed with the age and weight of the rat. The researcher utilizes effectively the a nimal to produce a vast amount of ascites on the basis of the results.