Objective To systematically evaluate the relationship between Cx43 and breast cancer by collecting relevant literature at home and abroad. Methods Through computer retrieval of PubMed, Embase, Web of Science, DynaMed, CNKI, and WANFANG Data six databases, together with the means of literature tracing, Cx43 expression in a large number of breast cancer tissues and the clinicopathological characteristics of the patients were collected for the case-control study, The search period was from the building of the databases to April 2017. The literature was selected according to the inclusion and exclusion criteria and the NOS scale was used to evaluate the quality of the literature, and the data were then analyzed using Review Manager 5.3 software. Results A total of 14 case-control studies were included in the study. There were 632 cases of breast cancer specimens, 240 cases of normal breast tissue specimens and 167 cases of mammary hyperplasia tissues. Meta-analysis showed that the positive expression rate of Cx43 in the breast cancer tissues was significantly lower than that in the normal breast tissue and the breast hyperplasia tissues (P < 0.05), the positive rate of Cx43 expression in the breast cancers of TNM stage III and IV was significantly lower than that in the breast cancers of TNM stage I and II (P < 0.05), the positive expression rate of Cx43 in the histological grade III of breast cancers was significantly lower than that in the histological grade I and II (P < 0.05), and the positive expression rate of Cx43 in the breast cancers with lymph node metastasis was not significantly different from that in the breast cancers without lymph node metastasis (P > 0.05). Conclusions Current studies have shown that Cx43 expression is closely associated with the clinical characteristics of breast cancers, but because of the small number of cases, more high-quality studies are needed to confirm that.