: Analisysis of the effect of financial information, non - financial and macroeconomics to company underpricing when IPO.Initial public offering (IPO) is activity of company in order to public offer of primary share sale. A company who want to go public will be doing an IPO process. Phenomenon that happened commonly is underpricing. Underpricing is conditions which show that shares price at primary market was to low than first day of secondary market.This study aimed to analyse influence variabels which have an impact to underpricing at company when IPO in Indonesian Stock Exchange During 2007-2011. The factors studied were Return on Equity, Debt to Equity Ratio, Inflation Rate, Reputations Of KAP And Reputation Of Underwriter. The result of multiple regression model for this study indicates that Return on Equity, KAP Reputation and Reputation of Underwriter has a significant effect on underpricing at 5% significantly level, while financial leverage and inflationrate has no effect on underpricing.