To establish the normal fertile range in the results of the sperm zona-free hamster ova penetration assay (SPA) in Korean male, SPA using the low temperature ($4^{circ}C$) capacitation in TEST-yolk buffer (TYB) was performed in 67 fertile and 26 infertile men. Sperm parameters in routine semen analysis were also checked and compared with the results of SPA. Sperm concentration, motility and motility index (MI) were significantly higher in fertile group compared with infertile group: $96.0{pm}46.6$ vs $43.6{pm}31.9{ imes}10^6/ml$, $65.5{pm}14.8%$ vs $45.8{pm}23.6%$ and $46.31{pm}13.29$ vs 27.40{pm}17.98$, respectively. In fertile group, the hamster ova penetration rate (PR) was $98.5{pm}5.0%$ (80%-100%), and the penetration index (mean penetrations per ovum, PI) was $9.59{pm}6.35$(3.1-29.0). All the fertile men showed PI>3.0. In infertile group, PR was $24.6{pm}24.8%$ (0%-70%), and PI was $0.40{pm}0.42$ (0-1.3). Both PR and PI were significantly lower in infertile group. There was a significant correlation beween PI and sperm motility or MI, respectively, in fertile group whereas there was no correlation in infertile group. These data suggest that SPA using the low temperature capacitation in TYB can be a valuable diagnostic tool for the assessment of male fertility in vitro and provide an important supplement to the traditional tests of sperm quality.