Objective To compare the conventional marrow collection with new marrow collection, in the number of cell, other tissues pollution and the background of the smear, providing the reference for future micronucleus test. Methods The mice was enthanasia and the sternums were taken. One group, using the conventional method of marrow collection, squeezing the marrow to the slide with fetal bovine serum; the other group, using 1-mL injector extracting fetal bovine serum 100μL, injecting into mice sternums and rushing out the bone marrow for circle smear. Results Two methods can meet the requirement of test, but the new marrow collection can acquire more number of cells, less the tissues pollution and more clear in the background of smear. Conclusions Comparing with the conventional marrow collection, the new method has more superiority to simplify the next cell counting.