615 mice

sensitized with living H615 cells

did not acqure the resistance to the challenge of same tumor and their mean survival was not longer than the controls’anymore. Pretreatment with H615 tissue homogenate even enhanced the growth of the ?implants of the tumor. At 60 days

the mean weight of the tumor transplatated co-nsiderablly increased than that of the controls (P<C0.05). Meanwhile

tumor incidence of this group went up from 80% of the controls to 100% (P>0.05). But for the others who received both of the treatment above

the more rapidly developing tumor had not been found. The possible reasons of this are discussed.The overall conclusion from this study was that the active immunizations enhanced rather than inhibited tumor growth.