Cordyceps sinensis (CS) is an herbal medicine that increases steroidogenesis in Leydig cells and improves male reproductive dysfunction. We have found that CS stimulates Leydig cell steroidogenesis through the protein kinase A and protein kinase C signaling pathways. In the present study, we sought to determine the mechanisms of CS-stimulated steroidogenesis in MA-10 mouse Leydig tumor cells. Using pharmacological approaches, we found that de novo protein synthesis, protein transcription, a calcium signal, and a mitochondria electrochemical gradient were required for CS-stimulated steroidogenesis in MA-10 cells. mRNA expression of steroidogenic acute regulatory protein was activated by CS. However, CS had an adversary effect on P450 side-chain cleavage enzyme activity, but not in 3β-hydroxysteroid dehydrogenase enzyme, in regulating MA-10 cell steroidogenesis. In conclusion, de novo protein synthesis, increased steroidogenic acute regulatory protein mRNA expression, and the mitochondria electrochemical gradient were involved in CS-stimulated steroidogenesis in MA-10 cells.