In this study a plant origin food supplement was prepared by using of class 2 Dashtestan date juice (pressed dates) and soy protein isolate (SPI). At first, physico-chemical as well as microbial properties of date such as pH, moisture content, total carbohydrates, total protein, and carbohydrate profiles by HPLC method were determined. Afterwards, pectinase enzyme (for clarification of date juice) was characterized by UV-spectrophotometry for determining of enzyme structure, total protein, enzyme activity, optimum temperature and optimum pH that were 55 C , and pH=5.3, respectively. Moreover, the holding time of enzyme and date juice in a range of 0-240 min was measured. The results revealed that 120 min holding time is preferd. Determination of amino acid profiles of date juice by amino acid analyzer method showed that, compare to the other essential amino acids, lysine has a noticeable amount of 194 mg% in date syrup . The results revealed that soy protein isolate has a protein content of 92.23 g%. The amino acid profiles of soy protein isolate that was determined by amino acid analyzer method implied that lysine with 4622 and leucine with 5266 mg% have a highly amount among other essential amino acids, furthermore, maltodextrin (as a drying aid) with DE= 5-19 was produced by enzymatic method and results indicated that maltodextrin with DE=9.5 is the best for drying of date juice. Furthermore, The optimum temperature for drying of liquid supplement with dry matter by 32% was determined from 130 to 140 C (inlet chamber) and a temperature of 90-95 C (outlet temperature) was determined. Finally, date-soy supplement with a basic formula and then, 5 different formulas with various protein to carbohydrate ratios were prepared and the results were evaluated by Design Expert software,version.7. Eventually, the protein to energy ratio of produced food supplements with basic formula was determined between 8.15- 10.30 that was higher than nutritional criteria that is specified by WHO-FAO