This paper is a review of the Genus Castanopsis in Guangdong Province and Hainan Province. It comprises 24 species and 4 varieties. Among them there are 1 new species ( C. semifabri X. M. Chen et B. P, Yu) ,2 new varieties(C. hainanensis Men. var. litoralis X. M. Chen et B. P. Yu,C. chinensis Hance var. hainanica X.M.Chen et B. P. Yu) ,1 new name (Gsect. Fissae X. M. Chen et B. P. Yu) and 1 new recordation to Hainan (C. fargesii Franch. ). The evolutionary tendency of their morphological characters is summarized preliminarily .