This paper examines order duration in Chinese Stock Market by the sample of 1,825,415 orders of 43 stocks of Shenzhen Stock Exchange in December,2003.Using ACD model,We find:(1) The evidence suppors spread hypothesis,depth hypothesis,volatility hypothesis,size hypothesis and the trade intensity hypothesis,and this result shows that microstructure characteristic,market condition,information and the desirability to trade affect investors' order submission strategy.(2) Rise-fall hypothesis is suppo...