Abstract: This review describes the form, distribution and physiological effects of silicon in plants and their absorption and accumulation. Studies showed that: 1 ) Silicon mainly deposits in the cuticular cells and cell wall of plant in the form of SiO2。nH2O. Silicon content in plants varies greatly among plant species. Generally, cultivated plants can be classified into three groups according to their silicon contents. We can also divide siliconphile and non - siliconphile plants according to their molecular ratio of silicon and calcium. Silicon contents in different parts of the same plant are not homogenous and changed with the growth phase. The accumulation of silicon in plants is affected by many environment factors.2)Plants absorb silicon mainly in the form of mono-sihcic acid. The ability of silicon absorption varies obviously among plant species. Rice can uptake silicon initiatively, and the absorption process is affected by their metabolic activities. Most of other plants mainly uptake silicon passively, but the possibility of selective absorption can not be excluded. 3)Silicon has effects on plant growth and development. It is an essential element for some plants (graminaceous plants, such as beet, scouring rush and some kinds of diatom), and it also benefits to many other plants. Silicon effects are mainly 1) on plant structure,2) on the physiological process of plant and 3) on the ability to resist adverse circumstances. Many plants showed a symptom of silicon shortage when all the silicon is removed from the growing environment. 4)Silicon influences the uptake and ulilization of other nutrient elements, and has different eyects on different elements. These influences often change during plant growth and development.