The effects of 4 disease-resistant inducers，including β-aminobutyric acid （BABA），
benzothiadiazole （BTH），salicylic acid（SA）and methyl jasmonate （MJ）on mycelial growth of potato late
blight pathogenic bacteria and sporangium germination rate were determined by using growth rate method and
sporangium germination inhibition method．The best medicament with suitable concentration was screened out
through pot experiment，and then field experiment was carried out by mixing the disease-resistant inducer with
fungicide．The results showed that these 4 disease-resistant inducers had no inhibitory effect on mycelial growth
and sporangial germination of Phytophthora infestans in vitro．The 4 disease-resistant inducers treatments
could lead to decreasing of late blight disease index and increasing of potato yield．The disease resistance to
late blight was strengthened along with the increase of concentration．Among all 4 disease-resistant inducers
BABA had the best disease-resistant effect．The suitable concentration was 50 μg · mL^-1，and its control effect
was 64.83%．Results of field trial indicated that the treatment of combing BABA with fungicides had better
effect than that of use of chemical fungicides．The final control effect on potato late blight could reach as high
as 81.28%，and potato yield was 43.7 t · hm^-2．The above results showed that BABA could better induce potato
resistance to late blight，and the combined use of chemical fungicide with disease-resistant inducer BABA was
recommended for field control．