In recent years, a large number of studies have achieved tumor targeting by mesenchymal stem cells (MSC)-based delivery system attributed to the tumor tropism of MSCs. Biomacromolecules and antineoplastic drugs loaded on MSC via internalization or cell membrane anchoring can be released or expressed at tumor site to perform their antitumor effects. The genetically modified MSC are extensively studied, however, the applications of MSCs in targeted delivery of antineoplastic drug with small molecules are not well summarized. In this review, MSCs homing mechanism and the distribution of injected MSCs is introduced; the examples of antitumor drug-primed MSCs and drug loaded MSCs are presented; the drug loading and releasing process from MSCs is also illustrated; finally, challenges and future perspectives of MSCs-based drug delivery system on realizing its full potential are prospected.