Change any of the environmental factors can basically have effect on processes on plant growth and ultimately on production and operation on crops. To study the combined effects of drought and salt stress on physiological characteristics of two varieties of Canola, a field experiment done in Mashhad (two kilometers to Ferdowsi’s tomb) with dry climate in split plot randomized complete block design with three replications. The main factor contains water stress (100, 125, 75 and 50 percent of water requirements, in order I₁, I₂, I₃ and I₄), salinity irrigation water (0.5, 5, 8 and 11 dS/m in order S₁, S₂, S3, S₄) and sub two Canola (Hyola 401 and RGS 003). Water stress and salinity decreased all the characteristics were evaluated. In separate combination salinity treatments and dehydration, effects of salinity water on reduction growth and yield are more than irrigation water and effect of low irrigation is less than the total effect of these tensions, that means in areas such as Mashhad, in low irrigation cannot use saline irrigation water for product Canola. The Hyola type (1801 kg/ha) more performance than RGS type (1326 kg/ha). RGS type in parameters of height, number of branches and dry weight is more excelence against Hyola, in reverse Hyola type significantly higher than RGS in yield and harvest index. The presented model more estimate LAI at the beginning and the end of the growing season, also in S₂I₄, S₄I₄, S₃I₄ treatments model has more errors than other treatments. Intended model overestimation the Canola height at the beginning of the growth season and underestimated in the end. Estimation of dry weight in the RGS type is more than Hyola type. While the estimates of dry weight are more accurate than the weight. However, the present model adequate for predicting Canola yield under drought and salinity and can be used to predict the performance.