A pot experiment was conducted at Isfahan University of Technology, Esfahan, Iran in order to investigate the effects of humic acid applied in a cadmium contaminated soil on the response of wheat and safflower cultivars to salinity. In this experiment two bread wheat (Ghods and Sistani) and one durum wheat (Yavaross) cultivars and also three safflower cultivars (Astrling, Arak 2811 and C 111 ) were evaluated under four salinity levels (0, 50, 100 and 150 mM NaCl) and two humic acid levels (0 and 1 gkg -1 ). Treatments were arranged as factorial based on a completely randomized design with three replications. Salinity decreased leaf chlorophyll content, potassium concentration in shoot and root and shoot and root dry weight but increased the concentration of sodium and cadmium in shoot and root in wheat cultivars. Salinity also decreased photosynthesis, stomata conductivity, leaf chlorophyll content, potassium concentration, root volume and shoot and root dry weight but increased the concentration of sodium and cadmium in shoot and root and the activities of catalase, ascorbate peroxidase and peroxidase in safflower cultivars. The interaction effect of salinity and cultivar on shoot dry weight was significant in wheat but it was insignificant in safflower. The extent of the reduction in shoot dry weight in wheat cultivars ranged from 14% at 50mM NaCl to 55% at 150mM NaCl salinity levels. Sistani was more tolerant cultivar as compared to Ghods and Yavaross under all salinity levels. Humic acid application decreased shoot cadmium concentration of Ghods, Sistani and Yavaross wheat cultivars by 40, 25 and 36%. While, shoot cadmium concentration was decreased by 16% in Arak 2811 but increased in Astrling and C 111 by 15% and 10%, respectively. All growth attributes of wheat and safflower cultivars were promoted by humic acid application. Humic acid application increased shoot and root dry weight of wheat cultivars in average by 18% and 26%, respectively, However, the interaction effect of humic acid application with salinity and cultivar was not significant in this regard. The shoot dry weights of Astrling, Arak 2811 and C 111 were increased 13, 14 and 28%, respectively. By humic acid application the activities of antioxidant enzymes, catalase, ascorbate peroxidase and peroxidase in safflower cultivars increased. In both wheat and safflower the positive effects of humic acid were greater on root than on shoot. The positive effects of humic acid on growth improvement of safflower cultivars were superior at lower than at higher levels of salinity. The results from this experiment showed that the application of humic acid in a cadmium contaminated soil could improve the growth of wheat and safflower under both saline and non-saline conditions. While humic acid application decreased the cadmium concentration in all three bread and durum wheat cultivars, the responses of three safflower cultivars were different in this regard. Key words: wheat, safflower, salinity, cadmium, humic acid