In this study, the characteristics and taste components of six different oyster mushroom cultivars (Gonji-7ho, Santari, Baekseon, Chunchu, Suhan, and Heuktari) were analyzed and compared. The Heuktari mushroom pileus had the lowest brightness index (32.8) and remained dark (brightness index: 30.5) even after blanching. The moisture content of the mushrooms was approximately 90%. The salinity and sugar contents were highest in Heuktari (5.7% and 7.1%, respectively). Gonji -7ho had the highest contraction rates, with a length contraction rate of 16.4% and thickness contraction rate of 23.9%. The total amino acid content was highest in Heuktari (537.8 mg/100 g), but the glutamine content contributing to umami taste was highest in Santari (59.4 mg/100 g) and the aspartic acid content was highest in Baekseon (33.1 mg/100 g). Among the 5?-nucleotide components, guanosine monophosphate, which enhances umami taste, was highest in Baekseon (0.7 mg/g). Baekseon was also calculated to have the highest umami taste concentration based on amino acid and nucleic acid contents (12.7 g/100 g). The results of this study serve as valuable basic data on the physicochemical characteristics of oyster mushroom cultivars grown in Korea.