In general, Cordyceps sinensis is much more popular than C. militaris, though both species contain quite similar bioactive ingredients and exhibit medicinal activities. Many bioactive ingredients have been isolated from C. militaris, such as adenosine, cordycepin, D-mannitol, and exopolysaccharides. C. militaris is claimed to have extensive pharmacological properties, such as: anti-inflammatory; anti-fatigue; anti-bacterial; anti-diabetic; improve lung, liver, and kidney functions; to be beneficial for treating cancer as well as male and female sexual dysfunctions. C. militaris is fast gaining momentum for its so-called health benefits, and it is often used as a substitute for C. sinensis. In view of the growing popularity of C. militaris, nowadays C. militaris cultivation for stroma is also done. There is a great diversity of compounds from different strains of Cordyceps and different artificially cultivated products. This study is to determine the optimum culture parameters integrated with substrate of choice to bring the indoor-cultivated C. militaris to a higher and more consistent level of quality. To achieve the above objective, the resultant products after growth were analyzed for adenosine, cordycepin, and D-mannitol using the high-performance liquid chromatography method. The optimum culture condition to produce a high level of adenosine is by using millet as solid substrate. It must be cultivated in the dark for the first 7 days and harvested on day 40. The optimum culture condition to produce a high level of cordycepin is by using soybean as solid substrate. It must be cultivated in the dark for the first 14 days and harvested on day 50. While a high level of D-mannitol is achieved with millet as the solid substrate. It must be kept in the dark for the first 7 days and harvested on day 50. The adenosine level decreased and cordycepin increased from day 40 of culture to day 50 generally.