Two new species of wasps belonging to the family Ephialtitidae, Praeproapocritus flexus sp. nov. and Proapocritus parallelus sp. nov., from the Middle Jurassic Jiulongshan Formation of southeastern Inner Mongolia, China, are described and illustrated. Praeproapocritus vulgates Rasnitsyn & Zhang, 2010 and six species of Proapocritus, P. densipediculus, P. sculptus, P. longantennatus, P. formosus, P. atropus, and P. elegans, all described by Rasnitsyn and Zhang in 2010, are first record from the Middle Jurassic of China. These two new findings supplement the morphological understanding of ephialtitids in the Middle Jurassic of China and broaden the diversity of ephialtitids in their by-gone ecosystems.