Phytolith analysis has been widely used to explore paleoenvironment changes and the origin of some crops. Phytolith biogeochemistry has received more and more attention because it resists to chemical erosion and degradation, and in particular the original information of plants are preserved in the occluded carbon in phytolith which is always difficult to be contaminate. Phytolith is produced in living plants and precipitated in the intra-cellular-and extra-cellular structures of their leaf, stem and root systems when monosilicic acid [Si(OH)4]is taken up by root under the driving force of transpiration. Silicon, oxygen and carbon isotopic compositions of phytolith are influenced by environment and regulated by plant physiology, and are different among organs of plant. Moreover, the silicon and oxygen carbon values of phytoltih normally tend to increase with its concentration up the plant in the transpiration stream. Of the three elements investigated, occluded carbon within phytoliths looks the most promising alternative indices for investigating the past environment at the moment. Carbon isotopic compositions of phytolith can be used in reconstructing the proportion of C3 /C4 grasses, and be promising for calculating atmospheric carbon isotope. The study of organic chemical components and the lipid in phytoliths may help to explain the reason of which fresh phytoliths extracted directly from grasses exhibit depleted isotopic values relative to the whole plant and a compression of the isotopic range between C3and C4 phytoliths relative to that for C3 and C4 grass.