Content and morphotype of phyoliths was studied in a soil chronosequence consisting of five soil profiles developed from basalt ranging in age from 10 000 years to 6.12 million years in tropical Leiqiong area. It was found that 1) the content of phytoliths in the soils, ranging from 1.54 to 21.95 g kg-1, was high in the surface horizon and decreased with the depth in profile; its drop was sharp from entisols to ferrosols and less significant from ferrosols to ferralsols, and then leveled off after entering ferrosols; 2) originated mainly from poaceae and palmae, the phytoliths ranged from 5 to 130 µm in size and appeared in 12 shapes, e.g. spherical echinate, dumbbell, fan, rectangular, square, saddle, hat, rod, tapered, crenate, round and others; The phytolith samples were all > 0.5 in warmth index, indicating the study area has basically been under a warm climate since 6.12 Ma.