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The objective of this study was to derive some Pedotransfer functions to predict the retention curve, the van Genuchten and the Mualem-van Genuchten parameters of some Gypsiferous soils. Consequently, 35 gypsiferous soil samples from different part of a semi-arid area were collected. The gypsum content was measured by acetone method, bulk density by volumetric method and the soil water retention curve was obtained using pressure plates apparatus. The gypsum of the soil samples was then removed by distilled water. Particle size distribution was determined into two steps: (i) with gypsum, by covering the particles with Barium Sulfate (ii) without gypsum, using hydrometery method. The easily obtainable variables were grouped into two groups (1) particle size distribution, bulk density and gypsum content, (2) bulk density, gypsum content, geometric mean and geometric standard deviation of particle diameter. The stepwise multiple linear regression method was used to derive the PTFs. Two types of parametric functions and two types of point functions are derived using of these variables. Comparison of the results indicated that the first group of variables had better prediction of water retention, the van Genucthen and the Mualem-van Genuchten parameters than the second group. The gypsum content appeared to be the second dominant parameter to predict the water retention at 0, -33, -100. -300. -500 and -1500 KPas. The t test method was used to compare the hydraulic parameters with and without gypsum. The results indicated that the removal of gypsum would increase the water retention at matric potentials of 0, -10, -33, -100, -300, -500 and -1500 KPas (p<0.01). Analyzing the data in more details, a significant difference between the hydraulic parameters was obtained for the soils with and without gypsum.