Abstract: 【Objective】The objective was to deeply study the spatial distribution of silicon fractions and factors influencing their availability in typical paddy soils in Hainan Island, so as to provide scientific basis for the efficient fertilization management of silicon nutrients and the development of silicon fertilizer industry.【Method】Sequential extraction technology combined with GIS and Stepwise Regression Analysis was applied to analyze the spatial distribution characteristics of silicon fractions and the main controlling factors of silicon availability in typical rice paddy soil developed from 5 parent materials（marine sediment, fluvial alluvial, basalt, granite and sandy shale）in Hainan Island. 【Result】The average available silicon content in typical paddy fields in Hainan Island was 44.79 mg/kg, and the available silicon content in all sample sites was less than 100 mg/kg, belonging to deficiency level. The high contents of soil available, organic and Fe/Mn-oxide silicon were mainly distributed in the northern and southeastern Hainan Island,which exhibited a complementary trend to spatial distribution patterns of the total silicon and amorphous silicon. The percent of soil available silicon in granite-based paddy fields was the lowest and that of the amorphous silicon was the highest, while the percent of soil available, organic and Fe/Mn-oxide silicon was highest compared to other parent materials. Except for the soil parent material, the availability of soil silicon in typical paddy fields of Hainan Island was mainly regulated by soil pH and available nitrogen.【Conclusion】Considering the serious silicon deficiency in typical paddy soils, it is urgent to implement reasonable fertilization and field management measures for paddy soils derived from different parent materials.