Abstract: This present invention relates to not only providing the conventional support for upper and lower back under normal circumstances of a proper sitting position, it even provides a self-adjusting experience and improved degree of lumbar support whenever a relaxed lean-backward seating posture is taken. This Self-Adjusting Cushion has executed without any compromise of losing the expected level of contoured support for the spine to be in proper alignment. Thus relieving and alleviating any possible fatigue or pain due to improper sitting position. Portable, Inflatable and Self-Adjusting Cushion for Upper and Lower Back Support is a sealed support device, which is configured and designed with a semi-oval shape structure to provide the contoured lumbar support. It is characterized with the following major components: 1. 3 rectangular-shaped slip-sheets of different breadths (depth) but of same length are attached horizontally and parallel to one another.