Abstracts. Kencur has been traditionally used as a medical plant for a long time. The potential content of kencur rhizomes as a medical plant lead to the idea of conducting a study that aims to determine the yield and antioxidant content of rhizomes cultivated in the shade and the effect of potassium fertilizer application. The research was conducted in two stages. The first stage was kencur cultivation in the AgroTechno-Park UB in Jatikerto from November 2020 to June 2021 designed according to the Split-split plot design (3 factor treatments). The main factor was the shade, sub plots were accession of kencur, and t doses of potassium fertilizer. The second stage was conducted in the Plant Physiology Laboratory to analyze the antioxidant content after the field experiment. The results showed that there was increased antioxidant activity in kencur rhizomes due to the use of potassium fertilizer and shade. The 25% shade produced higher antioxidants than 50% shade in both Lumajang and Nganjuk’s accessions.