Gastroserica herzi is a species of beetle of the family Scarabaeidae. It is found in China (Fujian, Guizhou, Guangxi, Heilongjiang, Hunan, Jiangxi, Sichuan, Zhejiang) and Korea.
Adults reach a length of about 6.1-6.6 mm. They have an elongate-oval body. The colour is variable. The pronotum ranging from black with only a faint red spot to light brown. The legs are often lighter. The dorsal surface is nearly glabrous.