For characterizing the flavoring uniformity in tobacco primary processing, a marker was screened by comparing the determined results of aromatic components in tobacco flavor samples with the volatile and semi-volatile aromatic components in cut tobacco before and after flavoring. The marker was quantitatively detected, and the influences of specimen size, sampling frequency and sampling interval on the content of marker were studied. The result showed that: 1) sclareolide (SER) was selected as a preferable marker, and a method for SER analysis was established, whose repeatability and average recovery were 3.63% and 95.95%-106.45%, respectively; 2) statistics analysis showed that the better sampling parameters were: sample size 30 g, 30 samplings at an interval of 60 s; 3) the flavoring uniformity coefficients at the output ends of flavoring cylinder, cut tobacco storing room and cigarette maker were 90.05%, 91.55% and 92.42%, respectively, which indicated that after flavoring, the distribution of flavor in cut tobacco was more uniform.