Abstract: Use of matrix attachment regions (MARs) is an important method to improve gene transformation and transgenic expression in plants. We constructed the TM2 MAR from tobacco at the flanking sides of the expression cassettes of reporter gene GUSA and selective gene NPTII in a plant expression vector, pBI121. The recombinant constructs were introduced into tomato plants by Agrobacterium-mediated cotyledon transformation. The transgenes were increasingly transformed and expressed in the transformants. Comparison of the effect of TM2 on different lengths of CaMV 35S promoter showed that the transcription enhancement of TM2 depended on the existence of promoter and showed partial functional redundancy. The effect of TM2 on transcription regulated by heat-inducible promoter indicated that the MAR did not change the regulation pattern but improved the expression level of the heat-inducible promoter. These characteristics of TM2 MAR fulfill the regulation requirements for transgenic expression and can be widely used in diverse plant biotechnology.