Silicon is a basic component of soil and rock. It can promote plant growth, enhance plant resistance, participate in biogeochemical cycle, regulate global carbon cycle and mitigate global warming trend. Based on the comprehensive introduction of fractions, availability, and biological cycling characteristics of soil silicon, this paper analyzes the contents of silicon and phytoliths in the soils of different ecosystems in China, and expounds the differences and influencing factors of available silicon and phytolith contents in the soils of different ecosystems in China. The research progress on the relationship between available silicon in paddy soils and rice growth, the relationship between available silicon in forest soils and the formation of phytoliths and in the forests are mainly discussed in this paper. The mechanisms of phytolith formation and its important role in global soil carbon sink are also pointed out. Some issues which are to be further studied proposed in the last section provide a good reference for the development of study on soil available silicon and phytoliths in China in the future.