Shape

colour

transparency

structures and fluorescene of kerogen mainly from lower Crataceous Qingshankou Formation are studied with microscope under transmission light

reflected light and polarized light in conjunction with fluorescene and electronic scanning microscope.Kerogen is divided according to these optical properties into sapropelized

stablized

gelled and fusited mace-rals

and three major groups of kerogen

such as sapropel type

mixed type and humut type

are made relative to proportion of each component.On the basis of this study

it is identified that the kerogen from the Qingshankou Formation is mainly of sapropel type in the stage of maturity or nearly maturity.Although the type of kerogen could hardly be distinguished by means of chemical method for samples from outcrop or highly evolved one

yet it can be detected on the basis of their optical attributes.