The present invention discloses a method for manufacturing red mold dioscorea, and the method comprises the following steps: washing and cutting a fresh dioscorea into pieces with a specific dimension; drying the pieces of the fresh dioscorea for making the dried dioscorea contain a specific water content and a specific sulfur content; adding some water with an appropriate ratio to fresh dioscorea or dried dioscorea; sterilizing the dioscorea; after the dioscorea being cooled down, inoculating the dioscorea with Monascus species; cultivating the dioscorea with an appropriate temperature, an appropriate humidity and an appropriate shacking frequency for an appropriate time period; and drying the cultivated red mold dioscorea with an appropriate water content.