Abstract: The aim of this study was to explore the population variation of sustaining fertilization ability of different laying hen breeds, the variation degree in population and the correlations among the related traits, which would provide a theoretical basis for setting up reasonable insemination interval for different breeds and breeding for sustaining fertilization ability in laying hens. Each 158 healthy hens from White Leghorn, Columbia Rock, Barred Rock and Rhode Island Red laying hen breeds of 27 weeks of age were used in this study. They were inseminated for two consecutive days. The eggs were collected for each laying hen for incubating from the 3rd day for 4 weeks. The egg production, daily/weekly fertility rate, average fertility rate in week 1-4, maximum days of fertilization and maximum number of consecutive fertilized eggs were calculated. The correlation coefficients among these traits were analyzed. The results showed that the daily fertilization rate decreased with days, but the extents were different in 4 breeds. The maximum days with the fertility rate greater than 90% were 10, 9, 8 and 11 days for White Leghorn, Columbia Rock, Barred Rock and Rhode Island Red, respectively. Except for day 4 (P=0.01), the daily fertility rate for the first 9 days were not significantly different among breeds (P>0.05); Except for day 13 (P=0.08) and 16 (P=0.19), daily fertility rate from day 10 to 18 was significantly different among breeds (P<0.05); Daily fertility rate from day 19 to 28 was significantly not different among breeds (P>0.05); There was no significant difference among breeds in weekly fertility rate in the first (P>0.05) and 4th week (P>0.05), but in the 2nd (P=0.005) and 3rd week (P=0.04) the difference was significant; There were significant differences in egg production, fertilized eggs number in week 1-4, average fertility rate in week 1-4, maximum days of fertilization, maximum number of consecutive fertilized eggs, fertilized eggs in week 1, 2, 3 and 2-3 among breeds (P<0.05), and all the above traits was the highest in Rhode Island Red hens; These traits also showed great variation among individuals within the breed, and the variation was small in Rhode Island Red and high in Columbia Rock and Barred Rock; The correlations among these traits were positive, and the correlation coefficients were high in fertilized eggs number between week 2 and week 1-4 (r=0.86, P<0.000 1) and between week 2-3 and week 1-4 (r=0.92, P<0.000 1). The results indicated that there were differences in the sustaining fertility ability among different breeds, and the breed-specific artificial insemination interval should be established; There was great variation in these traits within the breed,which indicated that further efforts can be made in breeding; The number of fertilized eggs in week 2 is an ideal trait for evaluating and selection for the sustaining fertilization ability of hens by reducing the labor in trait estimating without losing the accuracy.