Abstract:Pollen morphological characters of 22 species, 2 varieties and 2 forms from 15 genera of Malvaceae as well as Tilia chinensis of Tiliaceae were observed through light microscopy (LM) and scanning electron microscopy (SEM). Among these observed 26 taxa, pollen characters of 9 species, 2 varieties and 2 forms from 7 genera under LM were first reported, and pollen characters of 10 species, 1 variety and 2 forms from 8 genera under SEM were reported for the first time. The results indicate that:(1) the pollen grains of the observed 15 genera of the Chinese Malvaceae are usually large and spheroidal (dia. 54.4-211.5 μm) with spines, and aperture is colporate or pantoporate. The evolutionary trend of Malvaceae pollens is from a medium sized, 3zonocolporate pollen type with small, acute and bulbousbase spines to a larger polypantoporate pollen type with long, acute or blunt, flatbase and sometimes distinctly dimorphic spines. (2) The pollen morphological characters of Malvaceae have important taxonomic significance in the divisions of families, tribes, subtribes, and genera. Pollen characters support that Malvaceae can be divided into four tribes. Kydia and Hibisceae were ever placed in Bombacaceae, but their pollen morphological characters markedly differ from that of Bombacaceae. Instead, pollen characters support Kydia and Hibisceae as members of Malvacea and that Kydia can be placed in Hibisceae. (3) According to pollen morphology, we infer that Gossypieae and Malveae have a closer relationship and Abutilinae may be the most primitive group in the family, and Ureneae may be more advanced than Hibisceae. This study reports new pollen morphological characters and contributes to our knowledge on the taxonomy and phylogeny of Malvaceae.