Two new species of oribatid mites of the family Oppiidae, Pulchroppia roynortoni n. sp. and Lineoppia microseta n. sp., are proposed and described. Both are from dark loamy soil of Lagerstroemia forest from the Cat Tien National Park (Southern Vietnam). Pulchroppia roynortoni n. sp. differs from all the known species of the genus by the specific structure of rostrum and morphology of sensillus. Lineoppia microseta n. sp. is similar in its lineate anogenital region only to Lineoppia frouini Balogh and Balogh, 1983, but differs from this species in body length, notogaster integument, length of costular lines, interlamellar setae morphology, as well as in the position of some notogastral setae, of lyrifissures iad, and of apodemes 4. We present the first detailed descriptions of the ovipositor, gnathosoma and leg setation and solenidia of Pulchroppia and Lineoppia species. Diagnostic keys to the Vietnamese species of Pulchroppia and to known species of Lineoppia are presented. The genus Lineoppia is recorded for the first time in the Oriental region. Pulchroppia elegans is recorded for the first time in Vietnam.