Abstract:DP gene belonging to DP/E2F transcription family, encodes a dimeric chaperonin of E2F protein, which is essential for regulating cell cycle, DNA replication, growth, differentiation and apoptosis. According to sequence registered in SNG database, a DP gene was cloned using RT-PCR, and named as SlDP1 gene. SlDP1 protein is located in nucleus, contains conserved DNA-binding domain, dimerization domain, C-terminal domain and multiple phosphorylation sites. SlDP1 protein has 51.50% loop, 34.02% α-helixes and 11.87% β-strands. Exogenous hormone analysis manifested that SlDP1 gene was induced by ethylene precursor ACC. Results of abiotic environment response indicated that SlDP1 gene was not induced in leaves under wound and salt stress, but was apparently induced in salt-stress root. The expression pattern analysis revealed that expression of SlDP1 gene was stronger in flower, sepal and mature fruits. Taken together, our data establish a good foundation for studying the biological functions of SlDP1 gene in tomato life cycle.