The oyster mushroom is a widely cultivated edible mushroom in Korea. It is a regionally specialized crop in Gyeonggi-do, where 68% of the national production is produced. The present study was conducted to develop a new, highquality cultivar with stable cultivation. ‘Manseon’ is a new variety of oyster mushroom suitable for bottle culture. It was produced by mating monokaryons isolated from ‘HB-18’ and ‘P15159-16’. The optimal temperature for ‘Manseon’ mycelial growth was 26–29 °C on potato dextrose agar (PDA) medium and for primordia formation and the growth of fruit bodies the optimal temperature was 18–19 °C on sawdust medium. Spawn running required 30 d, primordia formation required 4 d, and fruit body growth in the bottle culture required 4 d. Regarding the characteristics of the fruit bodies, the pilei were round and dark grayish brown, stipe color was white, and stipe shape was short and thick. The yield per bottle was 192.7 g/1,100 cc, which was 9% higher than that of the control strain (Suhan-1ho). The physical properties of springiness, cohesiveness, gumminess, and brittleness of stipe tissue were 87.9%, 77.4%, 445.1 kgf, and 389.6 kgf, respectively.