This invention provides a rack apparatus, a delivery carriage and the automated storage and distribution system thereof. In the rack apparatus, there are only two racks at both sides of the rack apparatus extending in a generally vertical direction. And in the carriage, there are only two driving wheels. Therefore, both the rack apparatus and the carriage simplify the structure of the rack apparatus and the carriage and reduce the installation accuracy and the failure points thereof, but still provide new improvements to keep the carriage body horizontal with the ground.