Stripe rust, caused by Puccinia striiformis (Pst), is an important disease of wheat in Egypt. A total of nine and ten races were designated during two seasons. The most common race were 64E0, 66E0 and70E20 (23.07%, 26.92% and 23.07) during 2017/18. While, race 450E254, 206E174, 192E192,136E54 and 70E182 were the most common during 2018/19 at it was occurred at high frequency (22.50%,17.5, 15.0, 10.0 and 10.0% frequencies, respectively). The three races; 64E0, 66E0 and 70E22 were the widely geographical distributed, as each was detected in all governorates during the first season, While,the 136E54, 192E192 and 206E174 during sacond season. No virulences were occurred to wheat stripe rust monogenic lines with Yr1, Yr5, Yr10 and Yr15, during the two years of the study. Different frequencies of virulence of Pst isolates were obtained against wheat cultivars used. Cultivars; Misr3, Giza171, Sakha94, Sakha95, and Gemmeiza12 showed the highest level of resistance against the tested Pst isolates. High similarity was found between stripe rust populations in the six locations. The phenotypic diversity within different populations was characterized using the three main indexes; Shannon, Gleason and Simpson. Shannon index proved to be more suitable to accurately measure the phenotypic diversity between the tested populations, as it was sensitive to sample size, number of isolates, number of races and standard deviation of race frequency than the others. Monitoring the dynamics and variation of virulence in stripe rust populations, that provides the basic information needed for an anticipatory breeding program for disease resistance in Egypt.