Abstract: Using lsopropyl amine,p-methyl-phenol and methanol for simulating the amino,phenol and hydroxyl groups of silk fibroin respectively,the reaction of monochlorotriazine reactive dyes with nucleophilic groups of silk fibroin was studied with high-performance liquid chromatography(HPLC).The results showed that the reaction of monochlorotriazine reactive dyes with nucleophilic group of silk fibroin varies with different types of nucleophilic group with optimal reaction conditions at about 85℃and pH= 8 ~ 9 for the phenol group,and 95℃and pH= 9 for the amino group.However,for the hydroxyl group,more strong basic condition is preferred.Besides,taking into consideration the content and distribution of nucleophilic groups of silk,it was deduced that monochlorotriazine reactive dyes were suitable for dyeing silk under the conditions of 85~95℃and pH=8~9,and in respect of the effect of reacting with monochlorotriazine reactive dyes,phenol groups occupied the first place,followed by amino groups,while hydroxyl groups,negligible.