Abstract: ObjectiveBy analyzing the differential expressions of three Toll-like receptor(TLRs) genes including Mr-Toll1, MrToll2, MrToll3 in different tissues of Macrobrachium rosenbergii and expression difference of gill at different times after infection with Vibrio alginolyticus, the present study provided reference for revealing immune function of M. rosen-bergii TLRs in fighting diseases. MethodReal-time fluorescence quantitative RT-PCR was applied to detect relative ex-pressions of MrToll1, MrToll2 and MrToll3 in muscle, gill, hepatopancreas, heart, stomach, gut, hemolymph, nerve gan-glion, and eyestalk. The same method was also used to test the expression changes of TLRs gene after infected by V. algi-nolyticus. ResultMrToll1, MrToll2 and MrToll3 genes were expressed in all of the tested tissues and there also existed differential expressions. MrToll1 and MrToll2 genes highly expressed in gill among these tissues while the relative expression of MrToll1 and MrToll2 in gill were as much as 19.26 times and 20.03 times as those in hepatopancreases respectively. The expression of MrToll3 gene was the highest in nerve ganglions, which was as 10.13 times as that in hepatopancreases. After infected by V. Alginolyticus, mortality rate of M. rosenbergii increased as time spent, and reached the peak at 72 post infection(64%). After 72 h post infection, no more mortality occurred. After infection with V. alginolyticus, the expression of MrToll1 gene rose first and then decreased, and reached the peak 24 h post infection. The expression of MrToll2 went through a down-up-down-up variation, and reached the maximum 24 h post infection. The expression of MrToll3 gene de-creased sharply and maintained at low level. ConclusionMrToll1 gene is major response gene for gill resisting bacterial in-fection, MrToll2 gene may be involved in other immune activities of gill, and regulation mechanism of MrToll3 is unknown.