Oil field practices have proved that the part of the interpretation model significantly deviated from the reasonable scope in interwell tracer interpretation. It is considered too single and unilateral，and can not adapt to the complicated seepage flow in porous medium and the quantitative description. Therefore，after completed the design of tracer microscopic visualized experiment and natural long core displacement experiment, we try to qualitative and quantitative analysis the tracer characteristics and propose the reservoir characteristic of chromatographic effect of the tracer flow. The tracer microscopic visualization experiments show that the foundation of reservoir characteristics of the chromatographic effect exists，that is small molecular tracers can enter the irreducible water，unconnected pores and low permeability clumps. The natural long core displacement experiment shows that water breakthrough and flowing around are significantly in the small size of non-homogenous natural long core，and reservoir characteristic of chromatographic effect is also significantly，the migration speed between water and tracer is bigger. That must be considered in interwell tracer interpretations. It has an extremely important guiding significance for quantitative interpretation and qualitative understanding of interwell tracer monitoring.