To develop 50% loaded pumpkin seed oil microcapsules, using spray drying technology, with higher stabilities, the amount of surface oil and peroxide value of dispersion oil, during accelerated shelf life test, were selected as criteria for optimizing the composition of wall materials. The sodium caseinate and sodium starch octenyl succinate were tested as the main components of wall materials. Other antioxidants (sodium ascorbate, ascorbic acid and D-sodium erythorbate) and emulsifies (soybean phospholipid, mono- and diglycerides of fatty acids) were also applied and tested for the stability of pumpkin seed oil microcapsules. Polydextrose, a stuffing bulking agent, was also tested for substituting corn maltodextrin. As a result, the developed 50% loaded pumpkin seed oil microcapsules could be stored at ambient temperature for 24 months, and the surface oil was less than 2.5%, with the peroxide value less than 0.13% and the acid value below 1.0 mg KOH/g.