The Chinese fauna of the family Trigonalyidae Cresson, 1887, is revised, keyed and fully illustrated for the first time. Eight genera of this family (Bakeronymus Rohwer, 1922, Bareogonalos Schulz, 1907, Jezonogonalos Tsuneki, 1991, re-instated, Lycogaster Shuckard, 1841, Orthogonalys Schulz, 1905, Pseudogonalos Schulz, 1906, Taeniogonalos Schulz, 1906 and Teranishia Tsuneki, 1991) are recorded from China. The genus Ischnogonalos Schulz, 1907, is synonymized with Taeniogonalos Schulz, 1906. In total 40 valid species are recognized. Twenty species are new for science: Jezonogonalos elliptifera
sp. n., J. jiangliae
sp. n., J. luteata
sp. n., J. nigrata
sp. n., Lycogaster angustula
sp. n., L. flavonigrata
sp. n., L. nigralva
sp. n., Orthogonalys cheni
sp. n., O. clypeata
sp. n., O. robusta
sp. n., Pseudogonalos angusta
sp. n., Taeniogonalos bucarinata
sp. n., T. cordata
sp. n., T. geminata
sp. n., T. sculpturata
sp. n., T. triangulata
sp. n., T. tricolorisoma
sp. n., T. uncifera
sp. n., Teranishia crenulata
sp. n. and T. glabrata
sp. n. Two species are reported new for China: Orthogonalys elongata Teranishi, 1929 and Nanogonalos flavocincta Teranishi, 1929 (renamed to Taeniogonalos subtruncata
nom. n.). Seven new synonyms are proposed: Poecilogonalos yuasai Teranishi, 1938, and P. maga taiwana Tsuneki, 1991, of Taeniogonalos taihorina (Bischoff, 1914); Taiwanogonalos minima Tsuneki, 1991, and T. similis Tsuneki, 1991, of Taeniogonalos alticola (Tsuneki, 1991); P. intermedia Chen, 1949, and P. unifasciata Chen, 1949, of Taeniogonalos formosana (Bischoff, 1913). Six taxa are recognised as valid species: Bakeronymus seidakka Yamane & Terayama, 1983, Jezonogonalos laeviceps (Tsuneki, 1991), J. satoi (Tsuneki, 1991), Taeniogonalos alticola (Tsuneki, 1991), T. flavoscutellata (Chen, 1949) and T. gestroi (Schulz, 1908). Five new combinations are made: Jezonogonalos laeviceps (Tsuneki, 1991), comb. n., J. satoi (Tsuneki, 1991), comb. n., Taeniogonalos flavoscutellata (Chen, 1949), comb. n., T. gestroi (Schulz, 1908), comb. n. and T. lachrymosa (Westwood, 1874), comb. n. Lectotypes are designated for Lycogaster violaceipennis Chen, 1949, Poecilogonalos flavoscutellata Chen, 1949, P. rufofasciata Chen, 1949, and P. tricolor Chen, 1949.