Various experimental models have been proposed for predicting solar radiation. These models have been defined to base on location and special conditions of each world’s cities. In this paper, radiation magnitude bases on available models calculated and compared with actual data of Yasuj city. Current data of solar radiation have been measured by Pyranometer CMP21. Results show that models of Tahran & Sari 1, Hottel, Yahghubi & Jafarpour and Daneshyar have had good agreement with the mean solar radiation without meteorological data. Although new coefficient based on angstrom derived to predict irradiation accurately (less than 6% error). Whiles base on atmospheric data, models of Benghanem et al. 3 & 4 with only 8% error can proposes for various years in this area.