)are widely accepted in aquaculture due to their better culturing performance than their parents. In order to facilitate diverse studies of the two species, such as genetic resource management and mapping of economic traits, we have constructed the parental linkage maps of the interspecific hybrids previously; however, the maps contained mainly AFLPs. In order to increase the quality of the parental maps and their applicability, they were densified with newly developed microsatellite markers in this studythe silver carp (male parent) mapthe number of assigned markers increased from 153 to 288 (including 93 new microsatellites) and from 271 to 511 (including 136 new microsatellites), respectively. The total length of the female map increased from65.8 cM, while the total length of the male map increased from . Syntenic comparison between bighead carp map and silver carp maps identified 22 homologous linkage groups, among them slight rearrangement of markers was found. The total length of the common intervals bounded by 76 parent- shared microsatellites was almost the same (femal1), which was significantly different from that of the intraspecific hybrids of silver carp (female:male=1), the mixed milt fertilization (interspecific hybrids, this study) caused the obvious increase of genome wide recombination rate. The hybridization of silver carp and bighead carp should not influence the recombination rate of either parent; they are morphologically similar to each other and interfertile and have identical karyoptypes. We believe that mixed milt fertilization avoide the competition among sperms of an ejaculation, enhancing genome wide recombination accordingly. This fry raising method is not favorable to the reservation of the elite haplotypes either newly formed or previouly selected, being one of the main reasons causing the depletion of culturing performance of these two species.