Functional foods are defined as the foods which have beneficial effects on body functions and help to reduce the risk of disease or improve the health, beyond basic nutritional functions. The consumption and acceptability of functional foods are increasing and therefore various compounds are added to foods to produce these products. Coenzyme Q10 is one of the compounds that are used to enrich food. It plays an essential role in the production of cellular energy, antioxidant activity and boosting the immune system. It is naturally present in many foods and all cells have the ability to synthesis it. As the age increases, the ability to synthesize coenzyme Q10 decreases from the food and the body encounters quenching Q10. It has also been shown that some of the diseases affect the body's lack of quantification of Q10. Food enriching with this combination is a way to offset this shortage. The purpose of this study was to form a complex coacervation of gelatin –basil seed mucilage in order to microencapsulate coenzyme Q10. The mucilage was extracted from basil seeds at pH=10, water/ seeds ratio=50: 1 for 20 minutes and then freeze dried. To provide microcapsules, an oily dispersion of CoQ10 was added to an aqueous solution of gelatin at 40 °C and homogenized at 14000 rpm for 3 min. The pH increased to 8 with 0.1 M NaOH. Then the basil mucilage solution was added to the emulsion at 40 °C and the thermal conditions were applied using a magnetic stirrer equipped with a heater for 10 min. The coacervates were formed by decreasing the pH with 0.1 M HCl. The system was kept at 10 0C for 12 h. For drying, the samples were frozen at -40 °C for 24 h and placed in a freeze dryer for 24 h. Encapsulation efficiency was calculated by estimating hexane extractable surface and total oil in microcapsules. The response surface method (RSM) and the Box-Behnken design were used to determine the optimum level of the four formulation variables for maximum efficiency, loading, turbidity and minimum supernatant absorption. The optimum efficiency, loading, turbidity and supernatant absorption were 83.698, 16.325, 0.979 and 0.227, respectively. Investigating the morphological characteristics of microcapsules by scanning electron microscopy (SEM) showed that the microcapsules had the spherical appearance and uneven surfaces. The results of Fourier transform infrared (FTIR) spectroscopy and thermal analysis (DSC / TGA) of microcapsule confirmed the formation of a gelatin – basil seed mucilage complex loaded with CoQ10. The release profile of Q10 from microcapsules was conducted in simulated gastric and intestinal fluid. Coenzyme Q10 release levels in the first 2 hours (gastric environment) was about 9.21% and within the next 6 hours (intestinal environment) was about 44.96%. The produced optimum microcapsule was used to enrich the milk. This study indicated that fortifying milk with microcapsule containing CoQ10, released its core gradually. Keywords : Encapsulation, Basil seed mucilage, Gelatin, Coenzyme Q10, Release systems