This research aim to examine some factor that influencing underpricing level that happened in Jakarta Stock Exchange (JSX) in maiden share determination at intial public offering (IPO). This factor is the change of financial leverage, the change of ROA (return an assets), the change of PER (price/earnings ratio), the change of EPS (earning per share), the change of inflation, the change of BI rate (rate of interest), and underwriter reputation as independen variable and mount underpricing dependen variable.

Population in this research is all of firm which listing in Jakarta Stock Exchange (JSX) during year 2002-2005 as much 43 company. Technique of collection sample is purposive sampling, in which the price of share offers at lower IPO by significance rather then by its price at closing the first day of secondary market. Hypothesis tested by using multiple regression analysis