Abstract: The fractal evolution of clinoptilolite (CP) during different crystallization stages was investigated using synchrotron radiation small angle X-ray scattering (SAXS) technique, in combination with other characterizations, such as X-ray diffraction (XRD) spectrum, scanning electron microscope (SEM), Fourier transform infrared (FT-IR) spectra and N₂ adsorption-desorption isotherms. Analysis based on the fractal theory, Porod's law and distance distribution function curves, reveals that the hydrothermal crystallization process of CP mainly involved three stages, including the induction period (0-29 h), the growth period (29-40 h), and the stable period (40-72 h). In which, the fractal structures gradually transformed from a loose mass fractal to a dense surface fractal with prolonged crystallization time, accompanying by particle size growth of the aluminosilicate species from 70 to 90 nm. These phenomena clearly indicated the redissolution and rapid nucleation processes. Subsequently, the gradual increase in surface fractal dimension and variations in hydrated interface layer thickness revealed that the reactivity of the aluminosilicate species was the main primary driving force for rapid formation of CPs during the growth period. After that, the disordered lamellar structures were further topologized into the highly ordered crystals of CPs in the stable stage. Furthermore, the adsorption behaviors and the adsorption heats of CPs synthesized at different crystallization stages for CO₂ and CH₄ were preliminarily explored.