The present invention relates to a blood pressure reducing composition and primers for Monascus purpureus NTU 568, wherein the composition is a red mold dioscorea (RMD) manufacturing by way of inoculating a Monascus purpureus NTU 568 to a dioscorea substrate and then treating the inoculated dioscorea with culturing and drying processes. This composition is able to reduce blood pressure and prevent the vascular wall from pathological deterioration therefore, the composition can be applied to clinical treatment and health food. Moreover, at least one nucleotide sequence for M. purpureus NTU 568 and the primers for the nucleotide sequence are also provided in the present invention in order to facilitate the person skilled in Monascus purpureus related art capable of accomplishing the strain (mutant) identification of the M. purpureus NTU 568.
