Blackening waxcaps (Hygrocybe subsect. Hygrocybe) are a group of colorful and attractive mushrooms. However, the species diversity of subsect. Hygrocybe in China is still poorly known due to the limited sampling. In this study, three new species of this group from Guangdong Province, China are described and illustrated based on their morphological characteristics and molecular analyses of the internal transcribed spacer and large subunit ribosomal DNA regions. Hygrocybe debilipes from grasslands of South China Sea islands is mainly characterized by its orange red to vivid red pileus, fragile stipe, and ellipsoid to oblong basidiospores; H. griseonigricans from woodlands is characterized by its whitish to dull yellow pileus, quick black discoloration and the globose, subglobose to broadly ovoid basidiospores; H. rubroconica from woodlands is characterized by the hemispheric to plano-convex pileus when mature, semitranslucent fibrose stipe, and globose to ellipsoid basidiospores.