Two types of transgenic creeping bentgrass with a bacterial gene (ipt) encoding the key enzyme in cytokinin production pathway were generated in our lab. Our recent study confirmed the overexpression of cytokinin in the ipt-transgenic plants. We also observed that ipt-transgenic plants maintained greener leaves and produced more tiller and roots after 14 d at 35 C compared to non-transgenic control plants. The objective of this study was to examine whether the delayed leaf senescence and improved heat tolerance of the transgenic lines was resulted from the evelated cytokinin production by regulating protein metabolism. Two-dimensional gel electrophoresis was performed to closely detect the quantitative changes of over a hundred proteins among four transgenic lines and the non-transgenic control line under both normal (20 C)and heat stress (35 C) conditions. The proteins with significant variation among lines were identified by mass spectrometry and their functions were discussed.