This study investigates to find out the effective mixed-asset portfolio combination by adjusting asset allocation among various types of funds. Especially it focuses on combining real estate fund and fixed-income security. The purpose of this research is to decrease multi-asset fund`s risk and to maximize its profit by constructing mixed portfolio strategy. The study is supported by empirical analysis of providing profitability and risk data of each type of asset. The empirical data are covered from 2002 to 2008 and divided Seoul to four official group of office district. This study analyzes multi-asset fund by combining real estate fund with various type of assets and providing profitability and risk analysis of each combination. The empirical analysis is executed by adjusting government bond`s composing ratio in the multi-asset portfolio from 10% to 90%. The consequences show that by combining 90 percent of real estate fund with 10 percent of government bonds in a portfolio, forming a multi-asset portfolio, it diversifies portfolio`s risk under approximately 20%. The result of this study suggests that in order to develop and vitalize real estate fund as well as multi-asset fund, a standardized office rating index is essential.