Purpose: To study the level of Ca and Mg in blood serum and milk of different extent of alcohol positive milk cow.Method: The CMT positive dairy cows were rejected.The alcohol-positive milk was tested using the 68% alcohol.Then,the 68% alcohol-positive milk was tested using 72% alcohol.After that,the 72% alcohol-positive milk was tested using 75% alcohol.The cows were divided into four groups: 75% alcohol-negative（control）,75% alcohol-positive,72% alcohol-positive and 68% alcohol-positive.There were 6 cows in each group,which were similar in milk production,parity,age,the lactation period.During the following three weeks,the blood serums and the milks from the cows in each group were gathered and the content of Ca and Mg detected.Results: The contents of Ca and Mg in the blood serum and milk of cows suffered from alcohol positive milk were higher than those in the negative milk.Conclusion: The Ca and Mg metabolic disorder in alcohol positive milk,redundant Ca and Mg neutralize the electric charge of casein to stability low down of casein,this made aggregation reinforce,all of these can induce alcohol positive milk.