compound Kushen injection (cKi), a medicine in widespread clinical use in china, has proven therapeutic effects on cancer. However, few molecular mechanism analyses have been carried out. To address this problem, bioinformatics approaches combining weighted gene co-expression network analysis with network pharmacology methods were undertaken to elucidate the underlying molecular mechanisms of CKI in the treatment of esophageal cancer (ESCA). First, the key gene modules related to the clinical traits of ESCA were analysed by WCGNA. Based on the results, the hub genes related to CKI treatment for ESCA were explored through network pharmacology. Molecular docking simulation was performed to recognize the binding activity of hub genes with CKI compounds. The results showed that the potential hub targets, including EGFR, ErbB2, CCND1 and IGF1R, are therapeutic targets of CKI for the treatment of ESCA. Moreover, these targets were significantly enriched in many pathways related to cancer and signalling pathways, such as the PI3K-Akt signalling pathway and ErbB signalling pathway. In conclusion, this research partially highlighted the molecular mechanism of CKI in the treatment of ESCA, offering great potential in the identification of the effective compounds in CKI and biomarkers for ESCA treatment. Esophageal cancer (ESCA) is widespread worldwide. According to Global Cancer Statistics 2018, it ranks seventh in incidence and sixth in mortality 1. The 5-year survival rate of ESCA is between 12 and 20% and differs substantially by sex 2. China is a high-risk area for ESCA, especially in some rural areas, where the incidence rate far exceeds that of urban areas due to lifestyle and environmental reasons 3. ESCA can be divided into esophageal adenocarcinoma (EAC) and esophageal squamous cell carcinoma (ESCC) according to histological classification. In recent decades, the incidence of EAC in Western countries has increased several times, and the proportion of ESCC has exceeded 90% throughout China 4,5. The introduction of chemo(radio)therapy and surgical therapy led to increased survival rates and reduced the incidence of recurrence 6. Because conventional methods do not adequately improve patient survival of ESCA, however, scientists are seeking more effective treatments. Recently, traditional Chinese medicine (TCM) has taken the world stage as complementary and alternative medicine 7. Compound Kushen Injection (CKI) consists of two herbs, Kushen (Radix Sophorae Flavescentis) and Baituling (Rhizoma Smilacis Glabrae). CKI mainly contains various anticancer ingredients, such as matrine and oxymatrine, which can inhibit the growth of tumour cells, overcome resistance to metastasis and multidrug resistance, and protect human immunity 8. CKI has been utilized in clinical practice for decades to treat various solid tumour types, including liver cancer, breast cancer, gastric cancer, and other cancer types 8,9. The analysis of medical data on 2,550 ESCA patients from 22 large-scale hospitals in China confirmed that CKI has been ...