Abstract: Phytolith-occluded organic carbon (PhytOC) can exist in the soil for thousand years, thus it is an important mechanism of long-term carbon sequestration in soils. In this study, Pleioblastus amarus forest in subtropical China was selected as experimental materials to discuss the distribution of silicon, phytolith, and PhytOC in a Pleioblastus amarus forest system. A microwave digestion method was used in this study to isolate phytolith from plant material and soil samples, and the PhytOC were determined by alkali dissolution-spectrophotometry method. The results showed that the contents of phytolith and PhytOC in a Pleioblastus amarus forest system decreased in the order: leaf > branch > culms. For different organs, there was significant linear correlation between Si content and phytolith content (R² = 0.98, P< 0.01), and between phytolith content and PhytOC content (R² = 0.52, P< 0.01), and there was significant negative linear correlation between total organic carbon content and PhytOC content (R² = 0.57, P < 0.01), and between organic carbon content in phytolith and phytolith content (R² = 0.17, P< 0.01). The PhytOC stocked in branches and culms accounted for 17.2% and 51.1% of total PhytOC stock in above-ground part, respectively. PhytOC stocked in leaves, branches and culms accounted for 0.59%, 0.21% and 0.28% of total organic carbon stock, respectively. The ratios of PhytOC/total organic carbon greatly varied in different organs. The phytolith contents in bamboo plants were linearly correlated with plant-available Si contents in the soil (R² = 0.91, P< 0.05), but poorly correlated with total Si contents in the soil (R² = 0.16, P> 0.05). The PhytOC production rate in the Pleioblastus amarus forest system studied was 40.2 kg·hm^-2·a^-1.