Abstract: Objective To explore the effects of homo sapiens partner of NOB1 homolog (PNO1) on the proliferation and apoptosis of epithelial ovarian cancer (EOC) cells. Methods Immortalized human ovarian epithelial Moody cells as well as human ovarian cancer SKOV3, Ho8910, Hey and OVCAR3 cells were cultured in vitro. The expression of PNO1 mRNA and protein in these cells was detected by qRT-PCR and Western blot, respectively. Then, SKOV3 cells were infected with lentiviral shRNA and the knockdown efficiency was detected. The proliferation of the cells was examined by MTT assay, Celigo cell counting and plate clone formation assay. The cellular apoptosis was detected by flow cytometry. Results PNO1 was highly expressed in EOC cell lines, compared with normal ovarian epithelial cells. After PNO1 knockdown by lentiviral shRNA, SKOV3 cells showed remarkable decreases in proliferation, colony formation abilities and apoptotic rates. Conclusions PNO1 knockdown can inhibit the proliferation of EOC and promote its apoptosis.