This study examines the changes in the inside ownership structure of companies after undergoes initial public offering in Taiwan. After initial public offering, the company¡¦s shares are in public possession while inside shareholders only possess part of its shares. To maximize their own interests, inside shareholders¡¦ ownership policies may vary due to different factors. Literature review shows that after IPOs the inside shareholders¡¦ share tends to be dropping but previous research focuses mostly on the changes in operating performance and ownership structure after IPOs. DeMarzo and Urosevic (2006) believe that the changes in inside ownership structure are due mainly to the trade-off between monitoring incentives and diversification. My study aims at companies which undergoes IPOs in Taiwan Stock Exchange Corporation or at GreTai Securities Market between Jan. 1st 1998 and Dec. 31st 2000. The article investigates how such factors as, corporate value, corporate risks, inside/outside shareholders¡¦ risk tolerance and the ownership structure of companies which undergoes IPOs, have effects on inside shareholders¡¦ share-holding adjustment speed, long-term share holding equivalence level as well as the long-term share holding differences between inside/outside stockholders and little investors. My findings substantiate my assumption that risk factors and monitoring incentives do have effects on the shareholders¡¦ ownership policies and that factors mentioned above do have different effects on the inside ownership structure of IPO companies. The more inside stockholders avert risks, the higher the share-holding adjustment speed becomes. In contrast, the more share inside shareholders possess during IPO, the lower the speed. Inside shareholders¡¦ optimal ownership policies are positively relevant to the corporate value and negatively relevant to corporate risks. They are also positively relevant to the risk aversion of investors. The degree of risk aversion on the part of both investors and inside shareholders also influences ownership structures of various shareholders.