Abstract: Objective To study the expressions of TGF-β1 and p21WAF1 in middle ear cholesteatoma and discuses their effects on cholesteatoma. Methods The expressions of TGF-β1 and p21WAF1 were determined by immunohistochemical S-P technology and computer image analysis in 20 specimens of cholesteatoma epithelium and 10 specimens of normal external canal skin. Results ① p21WAF1 and TGF-β1 could be detected in middle ear cholesteatoma and in normal ear canal skin.p21WAF1 was located at karyon,taking on yellow-brown pellet;TGF-β1 was located at cytoplasmic,taking on yellow-brown pellet.②The p21WAF1 positive rate in middle ear cholesteatoma was 65%;and there were almost no positive cells in normal external ear canal skin.p21WAF1 positive cells were detected in each layers,its LI was 28.9%±6.7%.Compared with normal ear canal skin,the expression level of p21WAF1 in middle ear cholesteatoma epithelium was higher than that in normal ear canal skin（P<0.05）.③ The TGF-β1 positive rate was 90% in middle cholesteatoma samples and 50% in normal ear canal skin.The positive cells were mostly in spine layer and granular layer in normal ear canal skin,low intensive,light-brown,and its LI was 13.3%±4.9%;in middle ear cholsteatoma epithelium,the positive cells scattered among all layers of the epithelium,and stained strongly in spine layer,high intensive,strong-brown,and its LI was 32.3%±5.7%,there was obvious difference （P<0.05）.④In cholesteatoma epithelium samples,the LI of p21WAF1 and TGF-β1 didn’[KG-*3]t have significant difference. But in cholesteatomatous tissues there was positive correlation between the LI average of p21WAF1 and the LI average of TGF-β1 (r=0.913，P<0.001) .Conclusion TGF-β1 and p21WAF1 can promote the occurrence and development of middle ear cholesteatoma,and they have positive correlation.

Key words: p21WAF1, cholesteatoma of middle ear, apoptosis