Abstarct: Salinity is one of the most important non-biological stresses that reduces the production of agricultural products as well as plant growth in soils of arid and semi-arid regions. Melatonin and salicylic acid, as plant growth regulators, also play an important role in improving plant resistance to abiotic stresses. To investigate the effect of these two growth regulators in reducing the effects of salinity on greenhouse tomatoes of Goldi cultivar, a factorial experiment baxsed on a randomized complete block design with three replications was conducted in 1398 in the research greenhouse of Shahroud University of Technology. In this experiment, salinity as the first factor with 3 levels (0, 50, 100 mM), growth regulators of melatonin and salicylic acid as the second factor with two levels of melatonin (0 and 10 μM), three levels of salicylic acid (0 , 1.5 and 2.5 mM) and zero level was considered as control as foliar foliar application and some morphological, physiological and biochemical traits were evaluated. The average fruit weight decreased from 68 mg in non-stress conditions to about 25 mg in salinity, while it increased to 128 g using salicylic acid and melatonin. The effect of salinity stress on all evaluated traits on tomatoes was significant. In general, salinity caused a significant decrease in morphological traits, maximum chlorophyll fluorescence, and quantum yield of leaf photosystem II. The results of this study showed that salinity reduces the growth of tomato plants under greenhouse conditions and the use of melatonin and salicylic acid to some extent can reduce the damaging effects of salinity and increase plant tolerance to salinity.