Objective To analyze the relationship between non-sentinel lymph node(NSLN)metastases and clinicopathologic features in breast invasive ductal carcinoma patients with 1, 2 positive sentinel lymph node(SLN). Methods A total of one hundred and ninety-eight patients with breast invasive ductal carcinoma from January 2013 to December 2017 were enrolled in this prospective study.Modified radical mastectomy was performed after SLN1-2 positive cases were confirmed by biopsy.Postoperative NSLN was counted and the relationship between NSLN and clinical factors was analyzed. Results The positive rate of NSLN in 198 patients was 40.9% (81/198), of which 80 cases were positive at axillary level I and only 1 case was positive at axillary level I and II.There was no significant correlation between NSLN positive and age (χ2=1.258), lesion grade (χ2=1.327), molecular typing (χ2=1.020), neoadjuvant chemotherapy (χ2=0.923), estrogen receptor (χ2=0.189), progesterone receptor (χ2=0.109), Ki67 (χ2=1.755) (P>0.05). The positive rate of NSLN in HER-2 positive patients was 56.9% (29/51), which was significantly higher than 35.4% (52/147) in HER-2 negative patients (χ2=6.136, P=0.034). Logistic regression analysis showed that HER-2 positive was an independent risk factor for NSLN (OR=0.031, 95%CI 0.012-0.615, P=0.022). Conclusion The risk of NSLN positive in breast cancer patients such as SLN1-2 positive patients is still high, and the risk of NSLN positive in HER-2 positive patients is higher. Key words: Breast neoplasms; Sentinel lymph node biopsy; Mastectomy; Non-sentinel lymph node