This paper was the result of the first study on the species composition of the bugs (Heteroptera) in Xuan Lien Nature Reserve, Thanh Hoa province from 2011 to 2013. A total of 157 species belonging to 111 genera, 13 families were recorded. Among them, some families were predominant such as Reduviidae (24.20 percent), Pentatomidae (19,10 percent) and Coreidae (18.50 percent). The 8 species are new record for Vietnam fauna: Laclisles rastellus Schiod., Diognetus intonsus Distant, Aenaria lewisi (Scott), Neojurtina typica Distant, Pyrrhocoris posthumus Horvath, Pyrrhocoris sinuaticollis Reuter, Lestomeius affinis Amyot et Seville, Yolinus albopustulatus China.