The choice behavior of Monochamus alternatus to Cedrus deodara essential oil and monoene was determined by Y olfactometry to probe the effect of host volatile on host choice of Monochamus alternatus adults and to provide the scientific basis for development and utilization of attractants. The results showed that the attracting action of 1/200 Cedrus deodara essential oil was the highest among all treatments, the essential oil of Chinese red pine, simulative of Cedrus deodara essential oil (a-pinene .' βpinene: limonene .' camphene: mycrene=50: 40:10: 1: 3) and odor source A (α-pinene: β-pinene=1: 1) had the obvious attracting action to female Monochamus alternatus adults, the simulative of Cedrus deodara essential oil had better attracting action to female Monochamus alternatus adults compared with odor source A, the attracting ability of odor source A was significantly higher than a-pinene and there was no significant difference in attracting action among Chinese red pine essential oil + Cedrus deodara essential oil, Cedrus deodara essential oil + simulative of Cedrus deodara essential oil and odor source A+odor source B(α-pinene: β-pinene=10:1).