Abstract: Objective: To explore a new method for cancer treatment by RNA interference (RNAi). Methods: The expression amount of PPO and the other gene were determined by real-time PCR or Western Blotting from the cell lines after RNA interference of the PPO gene on the cellular and intravital levels. Results: It was confirmed both on cellular and intravital levels that the expression of PCNA was reduced using RNAi and decrease of the ERK2 and MEK1/2 phosphorous protein helped to inhibit the growth of ovarian cancer cells. Conclusion: It is identified that the PPO gene relates to proliferation and phosphorylation from reverse and the ovarian cancer cells can be suppressed by RNA interference from in vitro to in vivo.