using two tea standard samples,two different extraction methods from GB/T 8313 were compared to determine catechin content.The boiling water extraction method was adopted from former national standard GB/T 8313-2002 "Tea-Determination of tea polyphenols content" and methanol extraction is in the current national standard GB/T 8313-2008 "Determination of total polyphenols and catechins in tea".The results showed that the contents of catechins is very similar in water extraction method by three technicians,but have significant differences(at the 5% level of significance)when using methanol extraction.Particularly,the contents of catechin esters are different at the 1% level of significance.These suggest that boiling water extraction method is more suitable than methanol extraction method in the determination of catechin content in GB/T 8313-2008.