A new concept for the stabilization and solidification of volatile radioactive wastes via gelation in a simple material system is introduced in this paper. Using sodium silicate as a reaction module and phosphoric acid as a catalyst or stabilization agent, CsCl is chemically converted to thermally stable compounds. The heat-treated product at 1000 ℃ contained a cristobalite crystalline framework and a glassy phosphorus-rich phase with a high Cs content. The morphology looked like honey flowing on the honeycomb. From TG/DT analysis, Cs could not be vaporized below 1300 ℃ by changing the aging conditions and molar ratio of Si/P. As a new concept, GRSS (gel-route stabilization and solidification) could give us the chance to make the high temperature waste conditioning process more stable and economical.