The crosslinking behavior of carboxylated styrene — butadiene rubber latex(CSBRL) by using gamma radiation with 2—ethyl hexyl acrylate(2—EHA) as crosslinking sensitizer has been studied in detail. In addition,the variation of the particle size and distribution of latex, chemical structure and thermal property of CSBRL with absorbed dose have been discussed. Also the radiation vulcanization mechanism of CSBRL has been suggested. The experiments showed that,the dose rate has small effect on the cross —link behavior of CSBRL,and the swelling ratio decreased rapidly with the increase of absorbed dose. Increasing the dose,the average molecular weight per crosslinked units(Mc) decreased and crosslinking density increased. When the dose is below 25kGy,no significant changes in the particle size and distribution of latex were observed. The micro—FTIR analysis and DSC curves confirmed the existence of grafting reaction accompanying the crosslinking reaction during the gamma irradiation with 2—EHA as sensitizer.