Objective:To investigate the indications of half-ICSI and the value of half-ICSI to prevent fertilization failure. Methods:The indications of the cases in the group of fertilization failure(fertilization rate was 0%)or lower fertilization rate(fertilization rate less than 30%) were compared with those in the group(fertilization rate more than 65%). Results:The fertilization rate of IVF(in vitro fertilization) in the half-ICSI was lower than that of conventional IVF. The indication of the borderline semen quality in the groups of fertilization failure and lower fertilization rate were 51.2% and 63.3%

respectively.Compared with the normal fertilization rate group

the indications in the groups of fertilization failure or lower fertilization rate were sig- nificantly differen(tP<0.05). 11patients out of 30 cases with 0% fertilization rate became pregnant due to the insemination method of half-ICSI and acquired the embryos by this means

accounting for 36.7% in the 30 cases. Conclusion:The border-line semen quality is the indication of half-ICSI. Half-ICSI is a choice of the insemination method to prevent fertilization failure

especially uncertain fertilization.