Two Monodiamesa species collected in all stages and both sexes from the Tibetan Plateau are erected as M. secunditibetica Han and Tang, sp. n. and M. bonalpicola Han and Tang, sp. n. Molecular analysis of barcodes (COI-5P) for some related known species confirms the species validity and allows inference of internal relationships. Detailed description, habitat ecology and geographical information of two new species are provided. Additionally, brief comments on some known eastern Palaearctic species of Monodiamesa are made to give insights on further study.