The effect of some agricultural practices such as farmyard manure, first irrigation, space of planting and phosphorus fertilization level on the infestation of canola plants with the cabbage aphid, Brevicoryne brassicae L. was studied at the Experimental Farms of South Valley University at Sohag, during 2003 i 2004 and 2004 i 2005 growing seasons. Results revealed that the number of B. brassr‘cae was significantly increased at 45 kg chemical nitrogen plus farmyard manure than at 15 or 30 units ! feddan of chemical nitrogen during the two seasons. The canola plants which irrigated at 45 and 60 days as a first irrigation harboured highly significant numbers of B. brassicee compared with the plants irrigated at 15 or 30 days. Results show also that the population density of B. brassicae was significantly increased when using 10 and 15 cm planting space and by increasing phosphorus fertilization levels during the two seasons of study, the high rate of phosphorous fertilization led to the significantly increasing of the population density of B. brassicae regardless of using 20 cm space of planting and 45 kg Pffeddan.