The present invention relates to a buoyancy-adjustable sinker that is used for fishing. The present invention includes a body portion made up of a hollow pillar-shaped upper cap having an open lower surface with a first through-hole formed on one side of its upper surface, a supporting rod as a rod-shaped member where the upper cap is disposed on one side of one end with the end passing through the first through-hole, and a coupling groove having a pillar-shaped body, a second through-hole through upper and lower surfaces of the body, and a ring-shaped groove in one side of an outer peripheral surface of the body, the other end of the supporting rod being disposed on one side of the supporting rod through the second through-hole, a first ring-shaped watertight member inserted into and coupled with the coupling groove and allowing an inside surface of the upper cap and an upper portion of the body portion to come into close contact with each other when the upper portion of the body portion is inserted into a space inside the lower surface of the upper cap, and a ring portion as a ring-shaped member made up of a first ring member formed at one end of the supporting rod and a second ring member formed at the other end of the supporting rod and having the same shape as the first ring member. According to the present invention, buoyancy can be adjusted to be suitable for fishing by the space between the body portion and the upper cap being adjusted by a user for various fishing environments. According to the present invention, the buoyancy of the sinker can be adjusted without sinker addition or removal even when the angler changes his or her gear or method during fishing, and thus the present invention is capable of adding to the anglers convenience.본원발명은 부력조절 낚시추에 관한 것으로 상세하게는 낚시시 사용되는 낚시추에 있어서, 속이 빈 기둥 형상으로 하면이 오픈되어 있고 상면 일측에 제1관통공이 뚫려 있는 상부캡과, 막대 형상의 부재로 일단이 상기 제1관통공을 관통하여 일단 일측에 상기 상부캡이 설치되는 지지봉과, 기둥 형상의 몸체와 상기 몸체의 상,하면을 관통하는 제2관통공과 상기 몸체의 외주면 일측에 링 형상의 홈이 파져 있는 결합홈
