Flavonoids are divided into several structural classes, including anthocyanins, which provide flower and leaf colors and other derivatives with diverse roles in plant development and interactions with the environment. This study characterized four Anthocyanidin Synthase (ANS) genes of Brassica rapa, a structural gene of anthocyanin biosynthetic pathway, and investigated their association with cold and freezing tolerance in B. rapa. Sequences of these genes were analyzed and compared with similar types of gene sequences of other species and found a high degree of homology with their respective functions. In the organ specific expression analysis, these genes showed expression only in the colored portion of leaves of different lines of B. rapa. On the other hand, BrANS genes also showed differential expression with certain time course of cold stress treatment in B. rapa. Thus, the above results suggest probable association of these genes with anthocyanin biosynthesis and cold and freezing tolerance and might be useful resources for developing cold resistant Brassica crops with desirable colors as well. The present work may help explore the molecular mechanism that regulates anthocyanin biosynthesis and its response to abiotic stress at the transcriptional level in plants.