This study was designed to determine the relationship between sperm acrosome reaction following ionophore challenge(ARIC) and hamster ovum sperm penetration assay(SPA) as assessment of fertilizing capacity of male. ARIC test and SPA were performed in 23 fertile and 19 subfertile men. The results were as follows; Sperm concentration was significantly higher in fertile group compared with subfertile group: $114.6{pm}64.40$ vs $61.3{pm}46.50{ imes}10^6/ml$. However, there were no significantly differences in seminal volume, motility and motility index, respectively. There was a significantly correlation between spontaneous and induced AR in fertile and subfertile group, respectively. ARIC value was significantly higher in fertile group, compared with subfertile group: $12.0{pm}5.57%$ vs $2.6{pm}4.96%$. Both Penetration rate(PR) and Penetration index(PI) were significantly higher in fertile group, compared with subfertile group: $97.4{pm}7.40%$ vs $64.9{pm}36$. 20% and $5.4{pm}2.88$ vs $1.5{pm}1.47$, respectively. The Positive predictive value(PPV), Negative predictive value(NPV), sensitivity and specificity of ARIC test (cut-off: 8.5) and SPA(PI cut-off : 3.0) in predicting fertility were 95.0%, 81.8%, 82.6%, 94.7% and 95.2%, 85.7%, 87.0% and 94.7%, respectively. There was no significantly difference in predicting fertility between ARIC test and SPA. In conclusion, ARIC test was shown to have a predictive value for fertilizing capacity comparable to that of the hamster ovum sperm penetration assay. Therefore, ARIC test may be a simple and cost-effective addition to existing semenology instead of SPA.