Abstract: Based on the investigation of 23 poplar farmland shelter belts and their site condition in Damiao town of Tongshan county and Shaodian town of Xinyi eounty,Jiangsu province, the protection mature age (PMA), quantitive mature age (QMA) and economic mature age(EMA) of poplar farmland shelter belt are analyzed by the classification of poplar’s growth type. And finally, the renewal age(RA) of different growth types is confirmed. The results are as follows:QMA,EMA and RA of growth type I are 14. 0 years, 18. 0 years and 19. 0 years respeetively;QMA,EMA and RA of growth type II are 15. 5 years,21. 0 years and 22. 0 years respectively;QMA,EMA and RA of growth type Ⅲ are 17. 5 years,24. 0 years and 25. 0 years respectively;As for growth type IV,its QMA is more than 20. 0 years,EMA and RA are 24. 0 years and 26. 0 years respectively.