Microscopy - base detection of malaria parasite is still the golden standard and plays an important role in malaria epidemiology. It especially contributes to early diagnosis and treatment to malaria. The microscopic network in the Northern mountainous province of Yen Bai was investigated in an effort to rate the qualities of both facilities and personnel. In term of malaria knowledge, the microscopists were found to be skillful and knowledgeable. Their practice of microscopy examination of making blood slides, Giemsa dyeing was good. A rate of 17.88 percent of the total examined slides were incorrectly performed or read. The rate of mistakes of species confusion or missing species was higher than the confusion of positive with negative slides. The microscopists at the district points were found to be more qualified than those of the inter-communal and communal points with a lower mistake rate (12.1 percent compared to 17.88 percent). To improve quality of the microscopy network, it is recommended to replace broken parts of microscopes, recruit new microscopists to replace those who have changed job, retired or have poor sight and so on
retrain them with updated techniques and check their quality with a more difficult check list.