English summary: A cross - sectional study was conducted on 50 white wine samples and 100 direct traditional wine processors at 50 manufacturing locations of traditional wine in Hau Loc and Nga Son districts of Thanh Hoa province in 2013 - 2014. The results showed that the general rate of contaminated alcohol in these districts for aldehyde was 88.0%, for furfural was 68.0% and for methanol was 44%.