Abstract: The analysis of the cork quality in relation with the health of the cork oak tree was characterized in eight cork oak forests of Northwestern Algeria (Oran), by a direct survey at Coveless CQ05 on 75 trees per stand. On average, the quality of cork expressed in the form of a quality index (QI) revealed a great variability of trees within and among forests. In fact, the quality indices (IQ) were very sensitive to the withering indices (ID). A strong negative correlation was detected in all the eight stations (r = -0.67). The results show the importance of appropriate silvicultural management to improve the quality of cork.