Objective To compare the adverse reactions and efficacy of dose-dense biweekly EC-T regimen with three-weekly TEC regimen in adjuvant chemotherapy for high risk breast cancer patients. Methods Fifty-one patients with high-risk breast cancer were divided into two groups according to random number table method. 27 cases in EC-T group: epirubicin 90 mg/m2, d1, cyclophosphamide 600 mg/m2, d1, every 2 weeks for 4 cycles followed by paclitaxel 175 mg/m2, d1, every 2 weeks for 4 cycles; 24 cases in TEC group: docetaxel 75 mg/m2, d1, epirubicin 75 mg/m2, d1, and cyclophosphamide 500 mg/m2, d1, every 3 weeks. All the patients in both groups received prophylactic granulocyte-colony stimulating factor 5 μg/(kg·d) from d3 of chemotherapy according to treatment protocol. The adverse reactions, disease-free survival (DFS) and overall survival (OS) were compared between the two groups using χ2 test. Results After a median follow-up of 31 months, the median DFS in the two groups were 28 months and 26 months, the 2-year DFS rates were 85.2 % and 79.2 %, and the 2-year OS rates were 100.0 % and 95.8 %. The EC-T group had higher median DFS, 2-year DFS and 2-year OS than the TEC group, but the differences were not statistically significant (all P> 0.05). The EC-T group had lower incidence of grade 3-4 leukopenia and neutropenia, grade 2-3 diarrhea than the TEC group, and no febrile neutropenia was observed in the EC-T group, the differences were statistically significant (all P< 0.05).However, the incidence of neurotoxicity, myodynia and arthrodynia were significantly higher in the EC-T group than those in the TEC group, the differences were statistically significant (both P< 0.05). Other adverse reactions, including anemia, nausea and vomiting, alopecia, liver dysfunction, and cardiac toxicity were similar between the two groups (all P > 0.05). Conclusion EC-T dose-dense biweekly regimen is well tolerated in adjuvant chemotherapy for high risk breast cancer patients with a trend to improve the DFS and OS when compared with the TEC regimen.