Objective Active whey protein preserved the active ingredients in cow milk processed with patented low temperature extraction technology. Protein contents up to 90%. In addition, it has many biological functions such as improving the nutrition status and strengthening immunity. It’s one of the important components in clinical nutritional therapy. This research is to study the effect potential mechanism and potentiof active whey protein on pancreatic carcinoma established in vivo model. Methods Xenotransplanted pancreatic carcinoma was established by panc-1 cell line, then divided into 3 groups, 8 mice of each randomly according to the different way of nutritional intervention: standard diet group (SD group), standard diet with soy group (Soy group), standard diet with active whey protein group (ABD group). During the experiment, animals' body condition was observed, weight of nude mice, tumor size and weight were recorded. And, compared the average survival time of mice. Meanwhile, we detected the glutathione levels in the blood and carcinoma. Results Weight loss of all mice in the three groups was observed. Weight of mice in ABD group (24.35±1.89)g was significantly higher than SD group (20.04±2.41)g 8 weeks after treatment (P<0.05). Volumn and weight of mice transplanted tumor in the three groups was no statistical difference. At the end point, compared with the SD group and Soy group [(56.00±5.29)d and (51.63±10.54)d, respectively], the average survival time of mice in ABD group(62.13 ± 2.47)d was significantly higher (P<0.05). There was no statistical difference between SD group and Soy group (P>0.05). The GSH level in the blood of ABD group was significantly higher than SD group and Soy group (P<0.05) when the level in the tumor of ABD group was lower but there was no statistical difference. Conclusions Active whey protein can prevent the weight loss in transplanted pancreatic mice, prolong the survival time, and this may be associated with preventing and curing cancer cachexia.