Today, the world's population is rising dramatically, and in line with this increase in the population of food and agricultural products, there must be an increasing in the number of problems associated with this process of agricultural land. Then it is necessary to use the maximum potential of this lands that product maximum yield without any damage. To reach this objective, land suitability evaluation is the most important way that can reach human to this objective. The main objective of this research was to compare different irrigation methods based on a parametric evaluation system in an area of 221402 ha in the Khosouyeh Subbasin of the Fars province, in the south of Iran. After preparing land unit map, 37 points were selected for sampling. Soil properties were evaluated and analyzed. Suitability maps for drop and gravity irrigation were generated using GIS technique. The results revealed land suitability of 98.42% of the case study was classified as permanently not suitable (N₂) and 1.52% currently not suitable (N₁) for gravity irrigation. On the other hand, land suitability of 77.73% of the case study was classified as permanently not suitability (N₂), 6.05% currently not suitable (N₁), 12.43% marginally suitable (S₃) and 3.79% moderately suitable (S₂) for drop irrigation. The limiting factors for both kinds of drop and gravity irrigation are soil depth and slope of land.