Two new genera, including three new species assigned to the subfamily Iscopininae Rasnitsyn, 1980 and family Pelecinidae Haliday, 1840—Archaeopelecinus tebbei, gen. et sp. nov., A. jinzhouensis, gen. et sp. nov., and Cathaypelecinus daohugouensis gen. et sp. nov.—are described from the Middle Jurassic Jiulongshan Formation of Eastern Inner Mongolia, China. This article documents the earliest record of fossil pelecinid wasps, extending the pelecinid existence to the Middle Jurassic and suggesting origination of pelecinid in northeastern China. Migration of pelecinid from East Asia to North, Central, and South Americas and evolution of pelecinid morphology (e.g., antennae, wing venation, body size, mouthparts) and dietary requirement also are discussed.