Objective:To study correlation analysis between Ki-67 and p53 expression in breast cancer tissues and preoperative neoadjuvant chemotherapy (NAC).Methods:From January 2014 to September 2015 in our hospital,73 cases of breast cancer patients treated with NAC were selected as the research object.NAC was administered to all patients for 3 weeks,and then the surgery was performed,and the biopsy specimens were performed before and after chemotherapy.Analysis of the effect of the patients and the expression of p53 and Ki-67.Results:In the 73 patients,CR had 24 cases,accounting for 32.88％,PR had 39 cases,accounting for 53.42％,OR had 63 cases,accounting for 86.30％.The results of pathological grading showed that grade 5 were 13cases,grade 4 in 26 cases,grade 3 in 22 cases,grade 2 in 9 cases,grade 1 in 3 cases.There was no significant difference in the expression of p53 in all patients before and after chemotherapy(P＞0.05).However,the expression of Ki67 was significantly lower than that before chemotherapy,and the difference was statistically significant (P＜0.05).The percentage of p53 positive expression in OR patients after chemotherapy was 34.92％,significantly lower than that of the negative expression of 65.08％,and the positive expression of Ki-67 was 71.43％,significantly higher than that of negative expression of 28.57％,the difference was statistically significant (P＜0.05).According to Pearson analysis,the negative expression of p53 in breast cancer tissues was positively correlated with the efficacy of chemotherapy(r=0.689,P＜0.06);Ki-67 positive expression was positively correlated with the efficacy of chemotherapy (r=0.714,P＜0.05).Conclusion:The expression of p53 and Ki-67 in breast cancer tissues and its effect on NAC were closely related to the preoperative,and it can be used to determine the effect of NAC by monitoring the expression of p53 and Ki-67.