We constructed the null mutants of fission yeast Schizosaccharomyces pombe rsml gene that is thought to be involved in mRNA export. Though rsm1 gene is not essential for growth, the null mutant strain constructed by replacing the rsm1-coding region with an $kan^{r}$ gene showed growth retardation and mRNA export defects compared to wild type strain. We constructed double mutants which harbor rsm1 null allele and mutant allele of genes involved in mRNA export. The mex67 or npp106 null allele, when combined with rsm1 null allele, showed an additive effect on growth retardation and mRNA export defects. On the other hand, the thp1 null allele restored the defects of growth and mRNA export of rsm1 null mutant. These results suggest that rsm1 plays a role in mRNA export from the nucleus.