Two new genera and two new species of family Taeniopterygidae, Mengitaenioptera multiramis gen. et sp. nov. and Noviramonemoura trinervis gen. et sp. nov. are described. These fossils were collected from Daohugou Village (the Middle Jurassic), Inner Mongolia, China. Hitherto, these fossil species from Daohugou are the oldest taeniopterygids. Both simple and complex venations simultaneously occurred in this group, which reveals that the early diversification of taeniopterids was well underway by the Middle Jurassic. Therefore, we prefer to adopt the Comstock’s opinion that the venation of taeniopterids was derived from the simple venation of the older group (such as Palaeonemouridae) at much ancient geological time ago. Some of the descendants carried this simple venation; others evolved into complex venation with many additional crossveins and branches. Two new genera and two new species of family Taeniopterygidae, Mengitaenioptera multiramis gen. Et sp. Nov. And Noviramonemoura trinervis gen. Et sp. Nov. Are described. These fossils were collected from Daohugou Village (the Middle Jurassic), Inner Mongolia, China Both Hitherto, the fossil species from Daohugou are the oldest taeniopterygids. Both simple and complex venations include this this group, which reveals that the early diversification of taeniopterids was well underway by the Middle Jurassic. Therefore, we prefer to adopt the Comstock’s opinion that that the venation of taeniopterids derived derived from the simple venation of the older group (such as Palaeonemouridae) at much ancient geological time ago. Some of the descendants done this simple venation; others evolved into complex venation with many additional crossveins and branches.