An air packaging device includes two layers of thermoplastic films, which form a sealable space where air is filled after first and second steps of heat-sealing process. The sealable space includes a number of independent sealed air chambers and a main air passage channel. The main channel has an air inlet. Each sealed air chamber is connected with the main channel by at least one one-way valve each including at least two layers of plastic films. At least two one-way valves are installed inside of the air chambers. This air packaging device increases the cushioning protection where the protection is most needed, but can reduce air chamber dimension at less important locations in order to reduce the volumetric size and, hence, reduce the shipping cost.