Objective To evaluate the efficacy and safety of nausea injection in prophylaxis of gastrointestinal reaction in- duced by chemotherapeutic agents,and compare them with those of kytril. Methods A randomized,self-crossover control trial was performed. All eligible patients were randomized into AB or BA group. The patients in AB group were treated by nasea in the first cycle and kytril in the second cycle,those in BA group were treated with the reverse order. Results In 43 patients enrolled in the study, 40 were evaluable for response. Nasea was significantly superior to kytril in the control of anorexia(70% vs 47. 5 % ) in the 12 hour period and nausea(57. 5 % vs 37. 5 % ) in the 24 hour period,P0. 05. In the control of vomiting in the 24 hour pe- riod,no statistical difference between the two drugs was observed but the response rate of nausea(75 %) was higher than that of kytril (55%) . The side effects of nausea were headache, feeling of head heaviness, dry month and fatigue,etc. All of these were mild and comparable with kytril in their frequencies. Conclusion Nausea can effectively prevent the gastrointestinal reaction in- duced by chemotherapeutic agents. It is superior to kytril in the control of anorexia and nausea. The side effects of nausea are mild.