Using data on Chinese industrial enterprises from 1998 to 2007,this paper firstly estimates the duration until new enterprises start to export and the duration until leaving from the export markets. We find that the average duration until new enterprises start to export is 2. 5 years and median one is 2 years and the risk function shows prominent negative duration dependence;the average duration until leaving from the export markets is 3. 4 years and median one is 3 years. And the hazard rate is an inverted U-shaped. Secondly,we use discrete time duration model--Cloglog model to analyze determinants of the durations,the results show that: the firm-level characteristics such as firm size,the average wage and whether they are foreign companies have remarkable influences on the durations. In addition,there exist significant differences in regional influences on the durations.