A wheelchair includes a seat, one or more wheels and a seat weight sensing mechanism. The wheel includes a brake mechanism for stopping the wheel. The seat weight sensing mechanism is placed below the seat and is connected to the brake mechanism. When the seat undergoes weight more than a predetermined value, the seat weight sensing mechanism tugs the brake mechanism to release the brake of the wheel. When the seat does not undergo a weight less than a predetermined value, the brake mechanism stops the wheel.本發明一實施例之輪椅包含一坐墊、至少一車輪軸及一坐墊重量感應機構。車輪軸包含一煞車裝置，用於煞停該車輪軸。坐墊重量感應機構設於該坐墊下方，並連接該煞車裝置。當坐墊承受超過一預設重量時，該坐墊重量感應機構牽動該煞車裝置解除該車輪軸之煞車；當坐墊承受未超過該預設重量時，該煞車裝置煞停該車輪軸。
