In the world, powdery mildews fungi Erysiphale have been recorded to damage severely on various crops belonging to host plant family Cucurbitaceae (Braun and Cook, 2012). In Vietnam, cucurbit fruits are kind of popular vegetable but powdery mildews heavily infected incidents are reported annually with significantly lost yield. Most of these powdery mildews are included in genus Podosphaera mainly due to the key of morphological classification in type of conidial germination, Fibroidium type, brevitubus sub-type and conidia with fibrosine (Braun et ai, 2001; Braun and Cook, 2012): Cloning and sequencing ITS regions of samples CS1-CS2 and MC1MC2 of powdery mildews fungi on cucumber (C. sativus) and bitter melon (M.charantia) by primer pairs, ITS5/ITS4 (White et ai, 1990) and of samples CP1-CP2, BP1, JG1, ET1 of powdery mildews fungi respectively on pumpkin (C. pepo) and other sub-host plants including E. tithymaloides, J. gossypifolia, B. pilosa, all from Ha Noi, Viet Nam, by primer pairs ITS1/P3 (Kusaba and Tsuge, 1995) obtained sequences then that have been registed in GenBanks with accession numbers (GA.) KM260704- KM260705, KM260715- KM26071 6 and KM260740KM260742 respectively. Analysing MP phylogenie trees based on these ITS rRNA sequences has already proven that powdery mildews fungi on all these samples from Vietnam belong to Podosphaera xanthii group with strong bootstrap value support 99 percent.