The Himalaya harbors numerous seed plant species, regarding as one of the most important biodiversity hotspots on earth. Due to its complex terrain and the separation of national boundaries, previous studies are limited to some countries or regions that there is a lack of the overall reflection of the number of plant species in the Himalaya. On the basis of species distribution data on the southern and northern slopes of the Himalaya collected by previous studies, as well as supplement of online databases, this study summarized the distribution of Himalayan seed plants in China, India, Nepal and Bhutan, and analyzed the characteristics, species composition similarity, floristic composition and elevational distribution patterns. The results show that the Himalaya harbors 11 875 seed plants species, belonging to 2 086 genera and 223 families, and 66.6% of which are herbaceous plants. Families containing a large number of species include Asteraceae, Orchidaceae, Poaceae, Fabaceae, Ericaceae and other families, and genera containing a large number of species include Rhododendron, Primula, Pedicularis, Saxifraga, Carex and other genera. Species similarity between Nepal and Bhutan is highest, while China and India have the lowest species similarity. Floristic composition analysis in family and genus both indicates that 51.6% and 54.2% of these seed plants are tropical element respectively. Most species occurred at intermediate and low elevations. There are high plant diversity and dissimilarity between different countries of the Himalaya, indicating that the overall understanding of the distribution and diversity patterns of the Himalayan seed plants shed light on future studies on the evolutionary history and conservation practice of the flora of the Qinghai-Tibet Plateau.