Abstract： Objective： To investigate the effect of peanut skins on mice with thrombocytopenia after chemotherapy through caspase pathways. Methods：A total of 84 Kunming mice were randomly divided into the normal group，the model group，the interleukin group，the low-dose peanut skin group，the medium-dose peanut skin group，and the high-dose peanut skin group， 14 mice in each group. Except the normal group， the mice models with thrombocytopenia were established by intraperitoneal injection of cyclophosphamide. After the successful preparation of the models，the low-dose， medium-dose and high-dose groups were respectively gavaged with 0.25 g/mL，0.50 g/mL and 1.00 g/mL water extracts of peanut skins at a dose of 5 mL/kg；the normal group and the model group were given equal amount of distilled water；the interleukin group received subcutaneous injection of recombinant human interleukin- 11(RHIL- 11) at a dose of 0.25 μg/g； both groups were treated once a day for seven days. After seven days，the levels of platelet and expression of Caspase- 3 and Caspase-9 were measured in each group. Results：Compared with those in the normal group，the expression levels of Caspase- 3 and Caspase- 9 in the model group were increased(P＜0.05)， the level of platelet was decreased(P＜0.01). Compared with that in the model group， the expression levels of Caspase- 3 in the medium- dose and high- dose groups were decreased(P＜0.05)，the expression level of Caspase- 9 in the medium- dose was decreased(P＜0.05)，the levels of platelet in the low-dose，medium-dose and high-dose groups and the interleukin group were increased(P＜0.05). There was no significant difference in the comparison of the expression levels of Caspase- 3 and Caspase- 9 and the levels of platelet between the the low- dose，medium- dose and high- dose groups and the interleukin group(P ＞0.05). Conclusion：Peanut skins can reduce the apoptosis of platelet and increase the platelet level to treat thrombocytopenia due to chemotherapy by down-regulating the expression of Caspase-3 and Caspase-9.