Objective: To study the tumor cytotoxicity of different extracts and different extraction methods of Periplaneta americana. Method: Cell counting kit-8 (CCK-8) method was used to compare the anti-tumor activities of different extracts (ethanol extract

petroleum ether fraction

ethyl acetate fraction and n-butanol fraction) and different extraction methods (percolation method

ultrasonic method

and reflux method) on three kinds of tumor cells (human liver cancer SMMC-7721 cells

human erythroleukemia K562 cells

and human colon cancer cell line HCT116). Result: The ethanol extract and ethyl acetate fraction of P. americana had inhibitory effect on the proliferation of above tumor cells in varying degrees

and the activity was strongest for ethanol extract; P. americana extracted by three extraction methods showed antitumor activity in vitro in varying degrees

and the percolation method had the strongest inhibitory effect on three kinds of tumor cells with minimal IC50 values. Conclusion: Ethanol extract of P. americana had strongest in vitro antitumor activity

followed by ethyl acetate fraction

and percolation method shall be used for extraction.