This study analyzes the relationships between soft dollar(brokerage commission) and characteristics of funds, and between brokerage commission and return on funds, using the data on equity funds of Korea from June 2008 to November 2011. The result confirms a statistically significant negative relationship between management & sales fees and brokerage commission, meaning that rather than raising management & sales fees, which could be easily recognized by investors, it is through brokerage commission, a hidden cost, which asset management firms indirectly compensate for their services. Meanwhile, the analysis on the relationship between brokerage commission and return on funds reveals that higher brokerage commissions lead to lower return on funds, meaning at least in short-term no contribution to increasing returns in the future. These results suggest the need for streamlining the system to alleviate conflicts of interest between investors and management firms in addition to effectively controlling for principal-agent problems.