The Commelinaceae diversity in Laos have been published, recorded 23 species belonging to nine genera, two species were the new record species in Laos namely Amischotolype glabrata, and Commelina maculata. The objective of this research was to study the diversity of Commelinaceae in Laos including the data of distribution, ecology, phenology, and conservation status of each species in Commelinaceae family. The research areas included four National Parks of Laos namely Nam Et-Phou Louey National Plank, Nakai-Nam Theun National Park, Hin Namnor National Park, and Dong Houa Sao National Park. The distribution of Commelinaceae in Laos is based on a study of four areas, Commelinaceae species in NKNT and DHS exhibited the highest similarity index (0.2857) with 10 species found in both National Parks. The ecology of Commelinaceae is highly diverse included dry evergreen forest, deciduous forest, evergreen forest, grassland, hill evergreen, limestone forest, mix deciduous forest, marshy places, open area, and secondary forest, the majority, including 11 species were discovered in marshy places. The Commelinaceae flowering from May to November, the highest flowering occurs in August, with 23 species blooming. The conservation status of Commelinaceae species in this research has been assessed by the IUCN, with five species recorded, including Commelina benghalensis, C. diffusa, Cyanotis axillaris, Cy. cristata, and Floscopa scandens. All of them have been classified as least concern (LC) species. The conservation status of Commelinaceae by the authors is also assessed using the IUCN Red List criteria, and these species were related to the IUCN Red List, these species of Commelinaceae separated into two groups, rare plants group including nine species namely Aetheolirion stenolobium, Amischotolype glabrata, Commelina maculate, Cyanotis arachnoidea, Dictyospermum ovatum, Murdannia japonica, Pollia secundiflora, P. thrysiflora and Rhopalephora scaberrima. Other species were in a commonly found plant group. The study of the conservation status requires further investigation to confirm its accuracy.
