Abstract: A laver Porphyra yezoensis sporophyte cDNA expression library has been constructed with λ phage vector and was randomly sequenced. The library consists of 1.52 × 10^6 clones with the recombinant percentage of 88.2%. The analysis of the 719 ESTs showed that the redundancy was 54.2% and the proportion of new EST was 65.7%. This library can be used as the base for gene cloning and analyzing, and further for functional genomic research of the laver. The nucleotide sequence data reported has been deposited in GenBank under accession nos. from CX873884 to CX874602.