Abstract: Brontispa longissima (Gestro) was a newly dangerous invasive pest in China. The feeding behavior of B. longissima was observed and leaf area of Cocos nucifera, Roystonea regia, Chrysalidocarpus lutescens and Caryota ochlandra consumed by the pest larvae was measured in the laboratory. The feeding trace of the early larvae was slender and the damage was light. The feeding trace of late larvae such as 3,4,5 instars was wide and the damage caused was serious. For the feeding trace of the adults was slender and deep, the damage caused was also serious. The consumed leaf area by the larvae varied from 40 to 48 cm~2. The leaves of C. nucifera, R. regia consumed by the early larvae were more than those of C. lutescens and C. ochlandra, but leaf area consumed by the late larvae was not significantly different among the four host plants. The models were constructed between the leaf area consumed and the larva instars.