Wheat leaf rust is one of the major diseases on wheat in Egypt which appears annually in virulence of different frequencies. In this investigation, leaf rust samples were collected from different locations of Lower Egypt during four seasons (2003/04 - 2006/07). The single pustule method of isolation was followed for each sample. Rust data were recorded as infection types and virulence frequencies were determined against 20 Lr genes, in monogenic lines, and some Egyptian genotypes. Virulence frequencies were very high against Lr's 1, 2a, 2c, 3, 16, 26, 11, 30, 2b, 14b, 15 and 42, but were the lowest against Lr's 9, 24, 3ka, 10, 12, 18, 21 and 36 and also the cv. Gemmeiza 9. The physiologic races were identified according to their reactions on the 20 Lr's and virulence formula (virulence/avirulence) was recorded for each race. Shift, appearance and disappearance of the physiologic races were demonstrated. Race groups TI---, PT--- and FT--- were the most dominant being virulent mainly against Lr's 1, 2c, 3 and 9.