Abstract: Origination of flints is rather complicated.The macro-feature and micro-texture of flints and their component characteristics of chemistry,minerals,and the silicon and oxygen isotope are studied.It is considered that the formation mechanism of flints from the central Pacific Ocean mountains is that foraminiferal limestone is substituted with the silica.The main characteristics of flints and analytic results are:there are white silicared stripes in flints.The same foraminiferal fossils can be found in the thin sections of flints.The remnants of foraminiferal limestone can be seen with the naked eyes in the part place of the same flints.The living environment of foraminifera is a normal marine(water depth 1000-3000 m).The composition of mineral is quartz,and the content of SiO₂ is over 96% in flints,and it has rather high value of δ¹⁸O(0.032) and lower value of δ³⁰SiO₂(0.000 4).Two groups of faults of NW and EW directions suffered by volcanic eruption many times are main features of geological structure in this area.The geochron of these mountains is from Cretaceous period to early Tertiary period,and they underwent a subsidence process because of the"crustal movement.Flints are formed in the environment of semi-deep sea.Volcanogene hydrothermal activity might be main sources of silica.