To provide a method and a device for lubricating a revolving drive mechanism of a construction machine which supply proper pressure oil as lubricating oil into a casing of each of a hydraulic motor and a reduction gear.

A gap is formed between a vertical wall 120A of a housing 120 formed integrally with the upside casing 104, and a vertical wall 104B at the right side of the upside casing; and the pressure oil from a pilot pump PLP is supplied into a through-hole of a cover 122 which is provided on its upper end surface. Throttles 126 and 124 for regulating flow rates are provided on the vertical wall midway through the gap and in the vertical wall in an upper position. The pressure oil passing through the throttle passes through a passage 120B the downside of which is opened so as to be supplied as the lubricating oil into the casing 130A of the reduction gear 130. Additionally, the pressure oil from an oil chamber 120A is supplied as the lubricating oil for the hydraulic motor 100 into the lower casing 104 via the throttle 126.