To observe the mechanism of Kangai injection in improving the clinical efficacy and immunity of breast cancer patients, and to explore its effect on PI3k / akt pathway. Methods:From January 2016 to September 2017, 90 patients with breast cancer who were received by our department were divided into control group and observation group by random number table method, with 45 patients in each group. The two groups of patients were given breast cancer-related basic treatment and chemotherapy, and the observation group was added Kangai injection treatment. The clinical efficacy, immune indicators, clinical benefit and of PI3k / akt pathway of two groups were analyzed. Results:1)The clinical effective rates of the two groups were observation group 86.23% and control group 68.11% (P<0.05); 2)immune function indicators of the two groups before treatment were not comparable (P>0.05). 3)The clinical benefit (KPS and the stability and improvement of KPS) were observed in the observation group, and the difference was statistically significant (P<0.05). The level of PI3K, pAKT and bcl in the two groups were decreased at all time points after treatment (P<0.05), and the level of bax was increased (P<0.05). However, the trend of marker protein concentration of PI3K / AKT signal pathway was significantly higher in the control group than in the observation group (P<0.05). Conclusion:Kangai injection can significantly improve the efficacy of breast cancer patients, which is achieved by improving its immune level. And it is closely associated with PI3k / akt pathway.