This study was conducted to investigate the effect of periods of sperm preincubation, concentrations andstorage periods of miniature pig sperm on in vitro penetration of porcine follicular oocytes. High concentration(1×10⁵, 2.5×10⁵, 5×10⁵, 1×10⁶, 5×10⁶ and 1×10⁷) did support sperm penetration than low concentrations (P<0.05).However, polyspermic oocyte rates were increased with high concentrations of sperm. On the other hand, spermpreincubated during 1, 2 or 5h could be penetrated than sperm preincubated during 0, 3 or 4h (P<0.05). Whensperm were storaged with different periods, in vitro pentration rates were significantly higher 0～2 days than3～4 days of sperm storage (p<0.05). These results indicate that sperm treatment factors can effect in vitropenetration in miniature pig.