To provide a lightweight cart and a bag with lightweight wheels which can be folded to be smaller and housed compactly in a portable bag excepting for a using time, which are easily taken out to be larger to be use and which require reduced burden to the hand when carrying.

Base boards 1, 2, 3 and 4 are formed, and hinges are fitted to the joint of the base boards 1 and 2 and the joint of the base boards 3 and 4. Next, slide movable mechanisms 11 are provided between the base boards 1 and 3 and between the base boards 2 and 4, a swingable wheel 5 and a swingable wheel or a straight moving wheel 6 are fitted respectively to the respective substrates (4 in total). The lightweight cart and the bag with the lightweight wheel composed of the lightweight cart and a bag can be folded compactly to be smaller and require the reduced burden for pulling.