During 2015-2017, species diversity of fireflies was investigated in deciduous forest area, mixed deciduous forest area and grassland surrounding the office buildings of Chulalongkorn University Forestry and Research Station, Lainan subdistrict, Sa district, Nan province. Five firefly species found in the areas were Asymmetricata circumdata, Lamprigera sp., Luciola terminalis, Luciola sp. and Pyrocoelia tonkinensis. In the past three years, there were quite a lot of physical changes in the study area such as building and road constructions, including invasion of the local people into the study area to burn the forests for mushroom and weaver ant larva fireflies inhibited in this study area. In the same study period, the research team also surveyed for firefly species diversity in Saraburi Area Development Project of Chulalongkorn University, Kaeng Khoi district, Saraburi province and found that there was some fireflies occurred in the two roadsides closed to the reservoir and along the ridge dam including around paddy study plots. Six species of fireflies were found such as Pyrocoelia tonkinensis, Inflata sp, Luciola substriata, Luciola sp.1, Luciola sp.2 and Sclerotia aquatilis. Moreover, a species of firefly, Diaphane sp., was collected in Doi Phuka National Park, Nan province.