Using the large scale sequencing, a novel human cDNA of 1,645 bp was screened from the cDNA library of human fetal brain. The cDNA contains an ORF encoding a 296-aa protein with a calculated molecular weight of 34.0 KD. Compared with that of current sequence databases, the putative protein was found to have 36% homology with protein-disulfide isomerase (PDI). So this cDNA was named PDI like (PDI-L) gene. Multiple tissue Northern blot analysis shows that PDI-L cDNA is expressed in heart, brain, liver, kidneys and so on. The ORF fragment of PDI-L cDNA was inserted into reconstructed pBV220 expression vehicle and its predicted expressive protein was obtained.