Background: Timely harvesting of Cordyceps militaris fruiting bodies and their bioactive compounds can reduce production costs. This study examined the effects of LED treatments on the production of fruiting bodies and nucleoside compounds in C. militaris at different growth stages of solid-state fermentation.Methods: C. militaris was grown on oats under different LED light treatments. Harvested samples were divided into fruiting bodies and fermented oats to dry, grind, extract, and determine the contents of adenosine, cordy-cepin, and pentostatin during cultivation by high-performance liquid chromatography.Significant Findings: The highest fruiting bodies yield (6.20 g dw/bottle), biological efficiency (92.75 %), aden-osine (2.22 mg/g dw), and cordycepin (2.57 mg/g dw) content in fruiting bodies were achieved on the 56th day under T5 white, LED blue light, LED blue light, and LED red light, respectively. LED white (1.31 mg/g dw), LED blue (1.23 mg/g dw), and LED red (1.25 mg/g dw) lights during days 35 to 42 resulted in the highest pentostatin content in fruiting bodies. Optimal yields of C. militaris fruiting bodies and their nucleoside compounds can be achieved through appropriate LED lighting and timely harvesting.