Abstract: In this paper, the mechanism of synthetic jadeite is investigated by sol-gel technique. The best gelation factors are studied from metal alcoholate concentration, pH value, amount of ionized water and water-bath temperature. The results of gemmological characteristics tests, polarizing microscope, X-ray powder diffraction and infrared spectrometer show that the gemmological characteristics of the synthetic jadeite are similar to those of the natural jadeite, and that the main crystal phase of synthetic jadeite is jadeite. The crystalline coversion of the sample is also very good. The sample of HTHP synthetic jadeite has the same characterized infrared absorption peaks as that of jadeite.