Recently, variations in or near Lin28B gene were reported to be associated with timing of human puberty by genome-wide association studies. There have been no reports on that in other mammals. In the present study, a fragment of 5,353 bp of goat Lin28B cDNA, encoding 247 amino acids, was amplified, which contains 744 bp coding region and 4,410 bp 3'-untranslated region (UTR). Two alternative transcripts of Lin28BS (encoding 247 aa) and Lin28BL (encoding 261 aa) were found. Eight mutations in 3'-UTR were detected in nine goat breeds, and the T allele frequencies of A2934T and C3053T in the five sexual precocious breeds were higher than that of the four sexual late-maturing breeds (p<0.05). This may indicate that both the 2934 and 3053 locus may be associated with the age of goat puberty. Our results might expand understanding of the biological pathway of Lin28B gene regulating the timing of mammal puberty.