Objective: The purpose of this study was to clone and sequence the cDNA of MH2 domain of Smad2 from human dental pulp cells. Methods: In this study, total RNA was isolated from primary cultured human dental pulp cells and reverse-transcribed into cDNA. The desired DNA product was obtained by nested PCR with 4 smad2 MH2 domain-specific primers. The segment was inserted into pBluescript II SK vector and the resulting plasmid was transformed into E. coli JM109. The double-strand cDNA of positive clone was sequenced by PE 317-A automatic sequencing. Results: cDNA of MH2 domain of Smad2 was obtained from human dental pulp cells. The sequence was consistent with that cloned from a human kidney cDNA library. No mutation was found. Conclusion: This study provides the first evidence of expression of Smad2 in human dental pulp cells, and indicates that TGF-B signaling may be mediated by Smad2 in human dental pulp cells. The cDNA cloned in pBluescript/S2MH2 could be used for further functional studies of Smad2 and MH2 domain in dental pulp cells.