Abstract: To reasonably utilize cheese whey which was a by-product from the manufacture of cheese and casein，the anaerobic fermentation process was developed to produce acetic acid from lactose in cheese whey.Then environment friendly deicers calcium magnesium acetate（CMA） can be produced with the acetic acid and CaO/MgO.A lactobacillus plantarum was used to convert lactose in cheese whey to lactic acid in the first stage，the conversion rate of lactic acid was 47.47%。Propionibacterium was used to convert lactic acid to acetic acid and propionic acid which could be separated by gas chromatography method in the second stage，and the conversion rate of acetic acid was 5.643%.Structure of CMA was verified by IR.This method effectively utilized cheese whey and reduced production costs of calcium magnesium acetate，will have a bright future.

Key words: cheese whey, fermentation, calcium magnesium acetate, environment friendly deicer