The Steel Composite Structural Pressure Vessel technology invented by the authors is summarized briefly in this paper. This is a unique advanced pressure vessel technology with wide applications in industrial fields. It has been awarded several National Invention Prizes in China and 20 Chinese and U.S. patents. Some outstanding characteristics of this technology are burst resistance, dispersed defects, safety in service, simplified manufacturing, and safe, reliable, economic online safety monitoring. These characteristics result from the multiple functional shell natures of this unique technology. There are four patented technological systems, namely, cross-helically wound flat steel ribbon on a thin inner shell high-pressure vessels, single U-groove steel ribbon interlocked and cross-helically wound on a thin inner shell large high-pressure vessels, total double-layer normal-pressure vessels and storage tanks, and single U-groove steel ribbons interlocked and cross-helically wound onto a thin inner shell low-pressure large storage tanks. These technologies can reduce fabrication cost by 20 to 50%. The first of these technologies was approved by the American Society of Mechanical Engineers (ASME) as Code Case 2269 in 1997 for high-pressure vessels with internal diameter ranging from 12 inch to 12 ft for use in the manufacture of ammonia, urea, and methanol well as large petroleum hydrogenation hot wall high-pressure reactors and other industrial equipment. (C) 2004 American Institute of Chemical Engineers.