This study was conducted from April 2012 to June 2012 to analyze breeding status of Black woodpeckers (Dryocopus martius) in the Gayasan National Park. Nest height, tree diameter which a nest built and altitude at the nest site of Black woodpeckers were 17.4 m, 63.8 cm and 587 m, respectively. A pair of Black woodpeckers completed a clutch in 4 eggs on 7 May and 3 of eggs hatched on 24 May 2012. Both female and male incubated eggs and never left eggs without one of parents. A male more contributed to build a nest than a female. Incubation duration was higher in a male than in a female. Nestlings made a begging call in a nest during the growing period. Begging frequency of nestlings increased from 11 days up to 20 days after hatching. After then, nestlings reduced begging and fledged a nest 24 days after hatching. This study provided information of breeding ecology to protect and manage population of Black woodpeckers which are endangered species in South Korea.