Micro-chemical experiment has been raised a new methods of chemical test and new technology during 80s of this century[1].it is reduce the pollution and the phenomenon is clear,fast,economy and safety.In this paper,the content of calcium and magnesium in dolomite was determined by micro-burette method and compared the results of the micro-burette and the routine analysis.There are no obvious differences in results[3].The relative standard deviation is less than 1.0%.The T-examine and F-examine value are in the allowed range.