Three new species of Gerronema are discovered from southern China. Gerronema angustum is characterized by its small basidiomata, greenish-green pileus, slender stipe, narrow, and close lamellae. Gerronema pubescence is characterized by its pubescent pileus when young, yellowish white to pale yellow lamellae that are lighter towards the margin, narrowly cylindrical to lageniform pleurocystidia, and absent cheilocystidia. Gerronema rhizomorpha is characterized by its yellowish white to brown pileus, well-developed rhizomorphs at the stipe base, absent cheilocystidia and pleurocystidia, and not growing on rotten wood. Molecular phylogenetic analyses of nrITS + nrLSU support the species delimitation. In this study, detailed descriptions, photos of the basidiomata, line drawings, and discussions with related species are comprehensively provided. A key to the known Gerronema species in China is also provided.