Haematococcus pluvialis, a unicellular green alga,is one of the potent biological sources for valuable secondary metabolite astaxanthin production.Methyl jasmonate(MeJA),a naturally-occurring plant cellular signal molecular,was found to induce secondary metabolites production.In this paper,the effects of MeJA on the cell growth,astaxanthin production and dxs gene expression of Haematococcus pluvialis were investigated in detail,which provides a theoretical foundation for cosmically manufacturing astaxanthin.The results showed that,the addition of different concentrations of MeJA restrained the cell growth of H.pluvialis and decreased total astaxanthin production also.Addition of MeJA could promote unit cell astaxanthin accumulation,and with the increased MeJA concentrations,the unit cell astaxanthin content showed the trendency that was first increased and then decreased.The optimum addition concentration of MeJA for astaxanthin production was 800 μmol/L.The highest yield of the unit cell astaxanthin content in H.pluvialis was 1.75?10^-9 mg,which increased by 23.24% compared with 1.42?10^-9 mg without MeJA.This study provides a simple means to increase astaxanthin production.RT-PCR analysis showed that dxs gene expression was induced by MeJA.With the treatment of 800 μmol/L MeJA, dxs gene expression levels were the highest.The correlation analysis results showed that,the astaxanthin content of H. pluvialis and the amount of dxs gene expression were in positive correlation,thus it can be seen that the dxs gene expression level can reflect the astaxanthin production of H. pluvialis, and dxs gene was a key enzyme gene of astaxanthin synthesis of H.pluvialis.