Abstract: Solar desiccant cooling cycle in combined mode with vapor compression refrigeration cycle in hot and humid weather of bushehr city was simulated. The main purpose of introducing the cycle was to reduce energy consumption, especially fossil fuel consumption, in vapor compression systems which are commonly used in buildings. To simulate the cooling cycle, a proper thermodynamic models and physical properties for each components of the system must adopted. A model for liquid desiccant system simulation was selected and coding was done in ESS based on experimental relations was used. The effects of regeneration temperature, thermal comfort condition and outdoor weather conditions such as air humidity were examined. In addition, in order to reduce further fossil fuel consumption in vapor compression cycle, the organic Rankine cycle was combined with vapor compression cycle so that required inlet work for compressor was supplied. Solar energy was adopted as the main required heat source for operation of organic Rankine cycle given the geographic potential of the area. A model of the solar system was simulated in TRNSYS and optimum values for all elements of the solar system were obtained based on Solar Fraction. Dynamic performance of the cycle in Bushehr city was analyzed in an area of 1000 m2 and with cooling capacity 50TR. The effects of significant parameters on the COP of the cycles, air outlet temperature and rate of energy consumption in the compressor were investigated along with the effect of outdoor condition on reaching thermal comfort. Results indicated that using solar energy with combined cooling system (vapor compression and liquid desiccant) cuts fossil fuel consumption about 50%. In addition, outcomes demonstrated that removing moisture from supply air by using a dehumidifier section in desiccant section of proposed cycle leads to 13% reduction in building cooling load in summer.