The present experiments was carried out in both experimental farm and laboratory of Plant Protection Research Institute, Sakha, Kafr El-Sheikh Governorate to study the population abundance of the Egyptian alfalfa weevil (EAW) and find out the influence of host plants on some biological aspects of Hypera brunneipennis (Boh.). Results indicated that by sweep net this insect adults had two peaks in January and April, while by photoelector recorded one peak in Apr. the larvae of EAW peaked once in March by the two methods during the two successive seasons.               The average number of the insect adults were 2.3±1.1 and 2.2±0.9 indiv./50 double strokes by the two methods sweep net and photoelector during the first season 2011/12, respectively. While, The average number were 5.9±3.2 and 5.7±2.7 indiv./50 double strokes during the second season 2012/13, respectively. The average number of the insect larvae were 11.6±6.8 and 11.9±7.3 indiv./50 double strokes by the two methods sweep net and photoelector during the first season 2011/12, respectively. While, The average number were 76.3±54.7 and 61.3±46.6 indiv./50 double strokes during the second season 2012/13, respectively.               The total period from the larval stage until the adult stage were the shortest (26±0.6 days) when the EAW was reared on Egyptian clover and the longest periods (34.8±0.5 days) were recorded on kidney bean with Significant differences according to different host plants.The adult longevity was the longest when the EAW was reared on Egyptian clover followed by fenugreek and Kidney bean with significant differences according to different host plants. The survival percentages of the larval stage and pupal stage were the highest (94.0% and 94.1%) when reared on Egyptian clover and the lowest percentages (65.0% and 83.3%) were recorded when the EAW reared on Kidney bean, respectively.