Consumer co-operatives in Korea have been rapidly growing and concerns about financing policy are increasing. This paper aims to identify the determinants affecting the capital structure of consumer co-operatives in Korea. There are two leading theories in finance that explain the capital structure, i.e., “trade-off theory” and “pecking order theory”. Though many empirical researches have investigated what are determinants of capital structure, listed corporations were the main target of interest. Using pooled panel regressions, we examine what determinants affect leverage ratio for the sample of iCOOP Korea, the largest consumer co-operative. The research findings indicate that profitability and firm size of o-operatives have significant negative (-) effect on leverage ratio, while the fixed asset ratio and asset growth have significant positive (+) relation with the ratio. In conclusion, determinants of capital structure in consumer co-operatives as MOB(Member-Owned Business) are different from those in IOB(Investor-Owned Business).