In this article, the concept of complementary and alternative medicine (CAM) was reviewed, and the functions and status of Chinese medicine in malignant tumor therapy as a CAM were summarized. The major usage of Chinese medicine as a CAM in treatment of malignant tumor are as follows: (1) Chinese medicine alone can be used as an alternative therapy for advanced patients who cannot benefit from chemotherapy or radiotherapy; (2) Chinese medicine can be used together with chemotherapy or radiotherapy as a complementary therapy to alleviate signs and symptoms, reduce toxicities and increase effect; (3) Chinese medicine can be used as an alternative therapy for elderly or patients with poor performance status (PS); (4) it can also combine with new technology (e.g., extracorporeal high frequency thermotherapy, radioactive seed implantation, and radiofrequency ablation) as a complementary treatment; (5) Chinese medicine can work with molecular target therapeutic drugs to increase efficacy and sensitivity, reduce toxicities, improve quality of life and prolong survival; (6) Chinese medicine can act as a maintenance therapy after surgery, chemotherapy and radiotherapy; (7) Chinese medicine can also be taken as a preventive measure in high-risk patients with pre-cancerous diseases or "tumor-free" status. Finally, the author concluded the prescription pattern of Chinese medicine in treatment of malignant tumor, and presented several clinical effective cases treated with Chinese medicine.