The dynamic interfacial tensions between five types of EOR surfactants and three types of Shengli crude oils were investigated, and the effect of surfactant concentration on interfacial tension was explored. The experimental results show that the different active components in crude oil could react under alkalescent condition and produce the surfaceactive soaps at the interface in situ. The interactions among the added surfactants, active components of crude oil and their products at interface together determined the characteristic behaviors of dynamic interfacial tension. Three types of characteristic dynamic interfacial tension curve might manifest as type "L", type "V" and type "W". The structure and concentration of surfactant and the type of crude oil were key factors impacting on the dynamic interfacial tension characteristics.