Measurement of poly(A) tail length is important to study mRNA stability. The conventional method involves a number of intricate steps and the use of radioisotope label. We have now developed an alternative simple method for the measurement of poly(A) tail length from mRNA, with which it is possible to check the quality of RNA extracted from tissues. The cDNA containing the full-length poly(A) tail was synthesized from mRNA, which joined the end of the poly(A) tail with a linker, by reverse transcriptase using a poly(A) tail anchor. Synthesized cDNA was amplified by PCR with a 5'-specific primer and a poly(A) tail-specific primer. The size of the poly(A) tail length of human alpha -globin determined by this new method was from 40 nt to 60 nt, which use the same as that determined by the conventional method.