Today after drinking water, the consumption of fruit juice has a special position in communities. Fruit juices are known as the rich nutritional source due to having large amounts of vitamins, minerals and phenolic compounds. Fruit juice is produced in two forms of cloudy and clarified types, which fruit juices such as apple, pomegranate, grape, cherry, pineapple, carrot juices are usually marketed in clarified type. Turbidity agents in fruit juices are starch, pectin, protein, tannin, cellulose and polyphenolic compounds, which are tried to be removed during clarification process. Clarification is one of the most important steps in fruit juice industry. Clarification could be conducted by microfiltration ,centrifugation, enzymatic treatments and application of fining agents (such as gelatin, bentonite, activated carbon, silica sol or kieselgel, polyvinyl pyrrolidone or a combination of these compounds). The clarification step affects on appearance, flavor and turbidity of juice. Fruit juice with no sedimentation or cloudy appearance has a high marketability. The most widely fining agent that is used in fruit juice clarification, is bentonite, because it has a high adsorption capacity and low cost. Sepiolite is another absorbent clay that its mine was first discovered and extracted in Iran in 2010. Due to the high surface area and porosity and the same mechanism of action with bentonite, it can be used as fining agent in clarification of fruit juice. In this study, the Iranian sepiolite clay that was activated by acid, heat, and heat-acid treatments, was used for clarification of apple and pomegranate juices.Response surface methodology (RSM) was used for optimization of clarification conditions to achieve the least turbidity in juices. The numeric factors at three levels were; concentration of activated sepiolite in range of 0.05-0.1%, temperature of clarification in range of 50-60?C and process time in range of 2-10 h. The results showed that the best conditions for clarification were; 0.05% clay concentration, temperature of 50?C and time of 7 h in apple juice and 2 h in pomegranate juice. By using these optimal conditions, the turbidity of juices were reduced 99.4% and 99.6% in apple and pomegranate juices, respectively. Then, the clarification capacities of various fining agents were compared. The results showed the treatments of sepiolite-gelatin-kieselgel and bentonite-gelatin-kieselgel in apple juice and the treatments of bentonite-gelatin, bentonite-gelatin-kieselgel and sepiolite-gelatin-kieselgel in pomegranate juice were the most active agents by reducing 99.7% turbidity. The results of this study illustrated that despite of minor differences between sepiolite and bentonite, sepiolite can be applied as a good replacer in clarification of fruit juice. Keywords: Activation, Apple juice, Bentonite, Clarification, Gelatin, Pomegranate juice, Sepiolite