To understand the trends of nutrients and harmful substances in the processing of rice bran oil (RBO). Three batches of RBO samples from three RBO factories, including crude oil, degum ming, dewaxing, deacidification, decolorization and degreasing were collected, Measurement of its vita min E, oryzanol and sterol and two harmful substances. Study its trends. Two harmful matters including benzopyrene (BaP), 3-chloro-1,2-propanediol (3-MCPD) and three nutritional contents including vita min E, oryzanol, sterol were determined. The trends of these substances change were studied. The vita min E decreased by 37.92%, oryzanol decreased by 23.05%, sterol decreased by 22.69%, BaP content of RBO decreased by 97.61%, 3-MCPD decreased by 80.47%, when compared with crude oil. BaP and 3-MCPD are produced, 3-MCPD shows a decreasing trend, and vita min E, oryzanol, sterol are decrease with different degrees during the processing of RBO.