OBJECTIVE:To investigate the quality of Isatis indigotica of different growing periods.METHODS:The property and the microscopic characteristics of Isatis indigotica of 1 or 2 growing years were identified and the contents of adenosine,indigo and indirubin were determined by HPLC. RESULTS:Isatis indigotca of 1 growing year showed wide liber and sparsely arranged parenchyma cells while Isatis indigotca of 2 growing years showed narrow liber and tightly arranged parenchyma cells. Without timely open-air drying or proper storage after harvesting,the Isatis indigotca was likely to experience color change of darkening in cross-section,increase of the content of the indigo,and decrease of the contents of adenosine and indirubin. The Isatis indigotica of too short growing period or two growing years were low in contents of adenosine,indigo and indirubin. CONCLUSION:The planting of Isatis indigotica should be standardized and which should be given a quality control to avoid the great quality difference arose from differences of habitat,planting and harvesting,initial processing and storing method,etc.