Objectives. Breast cancer is one of the major cancers in Chinese women. European Organization for Research and Treatment of Cancer Quality of Life Questionnaires (EORTC QLQ-C30 and QLQ-BR23) are now the most common and well developed instruments assessing the health-related quality of life (HRQOL) of breast cancer patients internationally, whereas there are relatively few Chinese studies. This study has two aims: to investigate the HRQOL and explore which dimensions of HRQOL play more important roles in breast cancer patients' overall quality of life in China and to explore the latent factor structure and the potential complementary relationship between these two EORTC questionnaires. Methods. This cross-sectional and descriptive study was performed from October 2014 to February 2015 in Qingdao Municipal Hospital, China. A total of 621 women breast cancer patients were enrolled. EOTRC QLQ-C30 and QLQ-BR23 were used to evaluate the HRQOL of the participants. The nonparametric test, multiple linear regression, and exploratory factor analysis (EFA) were the main statistical methods we used. Results. 608 participants completed the questionnaires with a response rate of 97.9%. The mean age of the participants was 48.0 years (SD=9.6). About 33% were illiterate or only finished primary school education. Almost half participants (47.4%) only adopted chemotherapy. HRQOL was significantly different with regard to patients' social-demographic and clinical characteristics. Age, residence, educational level, employment status, and TNM stage were five significant predictors for global health status. Pain, dyspnea, sexual enjoyment, and systemic therapy side-effect were main subscales which had a significant impact on the global health status for patients in different TNM stage. The EFA result suggested that QLQ-C30 and QLQ-BR23 were complementary questionnaires. Conclusions. The EORTC QLQ-C30 and QLQ-BR23 questionnaires provide complementary information regarding breast cancer patients' HRQOL, and depending on the different cancer staging functional/symptom scales which significantly contributed to the overall HRQOL differed.