Samples of Ae. albopictus, Cx. tritaeniorhynchus, Cx. quynquefasciatus, and Cx. vishnui, known as four important vectors of dengue fever/dengue hemorrhagic fever, filariasis, Japanese encephalitis, were collected from Lai Chau, Son La, Ha Giang, Phu Tho and Quang Ninh provinces from June 2011 to November 2012. The patterns of insecticide susceptibility to alphacypermethrinm, deltamethrin, lambdacyhalothrin, permethrin, cyfluthrin, etofenprox and malathion were determined. The results showed that: 1) Ae. albopictus was found susceptibile to alphacypermethrin, deltamethrin, lambdacyhalothrin, permethrin, cyfluthrin, etofenprox and malathion in most of study sites, but resistence to DDT and 2) Culex qvynquefasciatus, Cx. tritaeniorhynchus, Cx. vishnui were found resistant to alphacypermethrin, deltamethrin, lambdacyhalothrin, permethrin, tolerant to malathion.