We attempted to estimate the narrow-sense heritability of single compounds and whole profile of the anal gland secretion (AGS) with the regression method using several sets of relatives in the beaver (Castor canadensis). We used GC (gas chromatography) and GC-MS (mass spectrometry) to characterize and quantify chemical compounds in beaver AGS. We found that the heritability of single compounds seemed to be low, whereas the heritability of AGS profile appeared to be moderate. We conclude that many compounds might be involved in the coding of genetic relatedness, which was through a combination of analog and digital coding using many compounds