In order to study the effects of different levels of sulfur along with Thiobacillus and zinc on qualitative and quantitative growth of canola cv RGS003, a factorial experiment was conducted based on an RCBD with three replications at the Agricultural Research Station of Gonbad in 2013. The first factor was the application of sulfur with Thiobacillus at four levels, i.e. without sulfur and Thiobacillus (S0), 500 kg sulfur ha^-1 + 10 kg Thiobacillus ha^-1 (S1), 1000 kg sulfur ha^-1 + 20 kg Thiobacillus ha^-1 (S2) and 2000 kg sulfur ha^-1 + 40 kg Thiobacillus ha^-1 (S2). The second factor consisted of two levels of zinc: without zinc (control) and 20 kg zinc sulfate ha^-1. The results showed that all traits studied were significantly affected by sulfur with the exception of pod length. The effect of zinc was significant at 0.01 probability level of biological yield, seed yield, harvest index, straw yield, oil percent and oil yield. With an increase in application of sulfur mixed with Thiobacillus up to 1000 kg sulfur ha^-1 + 20 kg Thiobacillus ha^-1 (S2), all yield components increased except oil percent, but their further increase resulted in reduction of seed yield and yield components of canola cv RGS003. With the exception of oil content, the other traits studied were not affected by the interaction of sulfur by zinc.