Turf is one of the most important ground covers and it is one of the main elements of landscape design. It covers soil surface and provide a pleasant green space. Plant growth regulators, such as growth inhibitors, are widely used in turfgrass management to suppress shoot growth and inflorescences. TE is an inhibitor that used for reduction energy consuming, while enhancing turfgrass performance. The growth inhibitor trinexapac-ethyl (TE) [with chemical name: 4-(cyclopropyl-?-hydroxy-methylene)- 3, 5-dioxo-cyclohexanecarboxylic acid ethyl ester] blocks the final step in the biosynthesis of the biologically active forms of gibberellins, resulting in slower shoot growth. Trinexapac-ethyl offers the potential benefits of reduced mowing frequency, increased rooting, increased tiller density, traffic tolerance and reduced fertilizer inputs, without reductions turfgrass quality. In an attempt to quantify these potential benefits, this experiment was conducted to determine the interactive effects of trinexapac-ethyl and traffic on perennial ryegrass ( lolium perenne L.) clipping production, tillering, visual qulity, color, total chlorophyll, chlorophyll a and chlorophyll b contant, carotenoid and sluoble suger contant. This experiment was conducted in the split-split plot design based on randomize complete block design with three concentration trinexapac-ethyl ( 0, 0.25, 0.5 kg/ha) and three replicatios was conducted in the Isfahan University of Technology. Trinexapac-ethyl was applied to the main plots three times in year at six-week intervals between July and November. Artificial traffic was applied to sub-plots. The result showed that plant height, fresh and dry weight of clipping was reduced by applications of trinexapac-ethyl. Maximum perennial ryegrass growth suppression occurred at 2 week after treatment in each three times application. maximum of growth reduction for 0.25 and 0.5 kg/ha TE was 59% and 65% was respctively in each three cycles application. Traffic was extermly reduced height, fresh and dry weight clipping of perennial ryegrass and was more reduction in during time. Maximum reduction by traffic was ouccered in times that influence reduction of trinexapac-ethyl was most on growth. The interaction TE and traffic was significant for the plant height, fresh and dry weight clipping of perennial ryegrass. Trinexapac-ethyl applications resulted in increased number of tiller per plant with and without traffic, while traffic decreased number of tiller per plant. Application of Trinexapac-ethyl increased tillering to 21% compared to control. The result showed that total chlorophyll, chlorophyll a, chlorophyll b, and soluble sugers contant increased by applications of trinexapac-ethyl, while that TE hadn’t any effect on the carotenoid contant. Traffic treatment was not significant effect on total chlorophyll, chlorophyll a, chlorophyll b, and carotenoid contant, altought increased soluble sugers. Increased chlorophyll content could allow treated perennial ryegrass to have higher light harvesting capabilities for photosynthesis and also may give improved visual quality. Application trinexapac-ethyl did not show any significant effects on of color of perennial ryegrass. Applied trinexapac-ethyl enhanced perennial ryegrass leaf width in in each three times application. Overall, the results showed that application trinexapac-ethyl able to provide 62% reduction in the growth rate of perennial ryegrass and Continued until four weeks, so the concentration of 0.25 kg per hectare is recommended to reduced mowing frequency