abstract: In order to study the effect of Azotobacter and Arbuscular Mycorrhizal fungi (AMF) on the growth characteristics of safflower (Carthamus tinctorius L.) in different irrigation regimes, an experiment was conducted in 2010 at the greenhouse of Agricultural Faculty of Mohaggegh Ardebili University of Ardebil, Iran. The experimental design was factorial based on randomized complete block design with three replications. Treatments comprised of four irrigation regimes (field capacity, 20, 40 and 60% of drought stress) and four biological fertilizers (None-inoculated, inoculation with AMF and Azotobacter and their mixture as a mix-inoculated). Growth, yield and chlorophyll content of safflower decreased with increasing water stress. Seeds inoculation by combination of Azotobacter and AMF, increased leaf chlorophyll content, root and shoot length, shoot and root dry and fresh weight, grain yield at all irrigation levels. The highest safflower yield was for mix-inoculated at no stress treatment by 2.4 g per palnts. According to the results, seeds inoculation can alleviate the negative effects of drought stress on safflower plants, especially mix-inoculated treatment.