As one of the most important hormone,ethylene catalyses ripening of respiratory climacteric fruit including tomato.ETO (ethylene overproducing) regulates ACS (l-aminocyclopropane-1-carboxylate synthase) degradation through ubiquitin-26S-proteasome pathway and negatively regulates synthesis of ethylene in Arabidopsis.With the help of RNA interfering technical,construction of LeEOL1 (ETO like 1) silencing vector and Agrobacterium-mediated transformation of tomato would expound the role of ETO in system II ethylene synthesis.This work optimizes a regeneration and transformation protocol to obtain transgenic tomato.Conservative segments of LeEOL1 were cloned by RT-PCR (reverse transcription PCR).