The population fluctuation of oriental hornet during its active season (August- November) was weekly determined  using modified screen trap fixed on empty brood box  provided with some sealed honey combs for two successive seasons, 2007 and 2008. The obtained results revealed that the total numbers of trapped hornet were, 41242.5 individuals/trap and 9577.9 individuals/trapduring 2007 and 2008 respectively. The highest mean numbers of hornet individuals was recorded during October, for the two studied seasons represented 41.9% and 65.7% of the total trapped hornets. The highest wiped out colonies due to direct attack of hornet was occurred during October (29.03 % & 17.65%) for the two observed years, respectively. The percentage of the total destroyed honeybee colonies during hornet active seasons were 45.16% and 35.29% of the total wiped out colonies during each year. Many of the survived colonies, after hornet active season, were weak and unable for wintering. The percentages of finished colonies from them were 5.65% and 2.94% as a latent negative effect of hornet.  The percentage of total wiped out colonies were 50.81% and 38.24% for the two successive years in Giza region