Abstract: In order to study the differences of main chemical components in cut filler of different lengths,the differences of contents of routine chemical components,polyphenols,petroleum ether extracts,total volatile alkalis and non-volatile organic acids were analyzed by variance analysis.The systematic cluster analysis was conducted on the basis of the above chemical indexes,and the sensory evaluation was carried out to verify the results of cluster analysis.The results showed that:1) With the change of cut filler length,the contents of routine chemical components,polyphenols,petroleum ether extracts and non-volatile organic acids changed differently,and differed significantly.2) Cut filler samples of seven lengths were clustered into three categories:longer than 4 mm,1.60-4.00 mm,and shorter than 1.6 mm.3) The cut filler longer than 4.75 mm significantly differed from that shorter than 4.0 mm in overall sensory quality.