A walker having a brake mechanism includes a bracket unit, a plurality of sliding mechanisms, two control mechanisms, and two brake mechanisms. The bracket unit has two grips and a plurality of legs. The sliding mechanisms are respectively disposed on the legs, and each of the sliding mechanisms includes a roller disposed on the corresponding leg and a braking member fixed to one side of the roller. Control mechanisms are respectively disposed on the grips, each control mechanism including an operating member rotatable relative to the corresponding grip, the operating members being extendable relative to each other and extending upward relative to the grips Change between. One end of each brake mechanism is connected to the corresponding operating member, and the other end is engaged with the corresponding braking member for limiting the rotation of the braking member and the roller. When the operating members are respectively operated to rotate upward relative to the grips The brake mechanisms are separated from the brake member to release the restriction of the rotation of the roller.一種具有剎車機構的助行器，包含一支架單元、多個滑移機構、兩個控制機構及兩個剎車機構。支架單元具有兩個握把及多個支腳。滑移機構分別對應設置於該等支腳，每一滑移機構包括一設置於對應的該支腳的滾輪以及一固接於該滾輪一側邊的制動件。控制機構分別設置於該等握把，每一控制機構包括一能相對於對應的該握把轉動的操作件，該等操作件能在彼此相向延伸及相對於該等握把向上延伸的狀態之間變換。每一剎車機構一端連接對應的該操作件，另一端卡抵對應的該制動件，用以限制該制動件及該滾輪轉動，當該等操作件分別被操作相對於該等握把向上轉動時，該等剎車機構與該制動件分離，解除該滾輪轉動的限制。
