Abstract: Dormancy is the main reason of tumor recurrence and metastasis. Circulating tumor cells， tumor stem cells and micrometastasis may be dormancy cells. Targeted therapy and endocrine therapy can induce tumor dormancy in a long interval， that may reduce tumor relapse. Low-dose and short interval are two characteristics of metronomic chemotherapy. It can suppress tumor angiogenesis and induce antitumor immunity. That means it can induce tumor dormancy through tumor microconditions. But how to use lowdose chemotherapy and what the optimal doses and interval time are unknown. How it affect tumor cells’ actions is not clear， that needs indepth studies， including many investigations in vitro and in vivo.