Abstract: Aphis gossypii is major pest of Hibiscus rosa-chinensis in Khuzestan province, Iran. Seasonal population dynamics, spatial distribution and parasitism of the aphid were investigated during 2008-2010. The aphid population was monitored by leaf count and yellow sticky trap sampling methods. A. gossypii observed during moderate temperature months of year (October to April) in Khuzestan condition. The aphid migrates from weeds to H. rosa-chinensis in beginning of November. Density peak of A. gossypii was recorded during January to February. Yellow sticky trap was suitable sampling tool that could monitor early infestations of the plant by A. gossypii. Spatial distribution pattern of the aphid was determined by Taylor's power law. Spatial distribution of the aphid was aggregated on the plant. Parasitism percentage of the aphid by Aphidiidae wasps, especially during January to April, was high. Reduction of insecticide application during the parasitoid activity peak could be useful to the parasitoids conservation.