Abstract: To clarify the effect of environmental factors on the infection of soybean frogeye leaf spot, the authors conducted an experiment in a greenhouse with cultivar ‘Kenfeng14’, and carried out the spray inoculation of spore suspension when the 2nd three leaves were fully expanded. The study consisted of 5 temperatures (15℃, 20℃, 25℃, 30℃ and 35℃) and 6 treatments (12 h, 24 h, 36 h, 48 h, 60 h and 72 h). The experiment was completely randomized with 4 replications. The results showed that: there was no lesion during the leaf humid period of 12 h, indicating that 12 h of leaf humid was not enough to maintain the infection of soybean frogeye leaf spot; the diameter and the number of frogeye leaf spot could only be measured during 48 h leaf humid period at 15℃; the diameter and number of frogeye leaf spot could be measured during 24 h leaf humid period at 20℃-35℃; when the temperature was 30℃, the biggest effects on the diameter and number of frogeye leaf spot during 72 h leaf humid period could be observed, indicating that the condition was the most suitable environmental factor for the infection of frogeye leaf spot.