Abstract: The resistance to Nilaparoda(BPH)in 4 rice varieties at 30,45,60-days old plants and the correlations between the content of various free amino acids taken in rice sheath and 4 resistant parametrics including damage rating,amount of honeydew excreted;nymph survival and fecundity were studies.The results indicated that the total content and the content of mainly free amino acids in susceptible variety TN1 were higher than resistant variety 7105 in different growth ages.Generally the total content of free amino acids in the moderate resistant varieties Baosyan 2 and Fubaoai 21 were higher than in 7105 but lower than in TN1.The positive correlations significantly existed between the content of 4 amino acids (phenylalanine,Valine,glutamic acid and boleucine) and 4 resistant pararnetrics,also existed between the content of other 3 amino acids (asparagine,aspartic and leucine ) and 3 resistant pararnetrics.Otherwise,the result of feeding test showed that 5 kinds amino acids (asparagine,valine,leucine,serime and phenylalanine) have a significant pgagostimulative effect on the BPH fedding.