Abstract: The present study compared the differences of 14 morphological traits,including body weight(BW),snout-urostyle length(SUL),snout length(SL),head length(HL),shoulder-to-anal length(SAL),froe foot length(FFL),fore limb length(FLL),hind foot length(HFL),hind limb length(HLL),interorbital space(IS),internasal distance(INS),head width(HW),shoulder width(SW)and eye diameter(ED)between the females and the males of Paa spinosa in mountainous areas of the western Fujian.The results showed that except snout length,interorbital space and eye diameter,the other 11 measurements values were significantly larger in males than in females(P<0.05).The index of sexual dimorphism reached 0.068 and males Paa spinosa frogs were on average 7.3% longer in body length than that of the females.There was a significant correlation between snout-urostyle length,snout length,eye diameter and body weight in males(P<0.05).There was a significant correlation between snout-urostyle length,fore limb length and shoulder width and body weight in females(P<0.05).Multiple regression equations were used to estimate body weight and body traits.The equation for BW of the males was BW(♂)=3.620×SUL+0.626×HLL-5.847×ED+0.728×SL-269.868.Similarly,the equation for females was BW(♀)=2.914×SUL+1.502×FLL+1.521×SW-304.518.The sexual dimorphism of P.spinosa might be the result of natural selection and systematic evolution under the combined action of sexual selection on males and breeding pressure on females.