The effects of Arsenic (As) were investigated on four varieties of T. aestivum viz. PBW 343, PBW 550, PBW 621 and HD 2967 to elucidate the toxicity of As on morphological, physiological, biochemical and antioxidant processes of plant in early stage. The results showed that seed germination, root length, shoot length and biomass decreased gradually with increase in concentrations of As (125-750'M) and this decrease was biologically significant. The photosynthetic and respiratory activity of the test plants was also investigated. The decrease in chlorophyll and carotenoids content with increase in As content indicates negative effect of As on the photosynthetic pigments. However, the total cellular respiration increased with increase in As concentration and this probably may be due to the enhancement in respiratory enzymes which leads to high production of energy by the respective cells. The contents of water soluble carbohydrates and proteins increased with increasing As concentrations while their hydrolyzing enzymes i.e. ? amylase and protease were decreasing with increase in As concentration. The activity of antioxidant enzymes, superoxide dismutase and peroxidase followed the increasing trend indicating the induction of oxidative stress under high concentration of As. Further, among the various varieties HD 2967 was the most tolerant variety and PBW 550 was most affected variety.