Abstract: JDV Selective Trial Instrument is introduced for its working principle and constituent, usage and testing method. This device has three filter beds and can be used to measure simultaneously three high, middle and low permeability cores, and can be applied to simulate the entering fluid distribution in heterogeneous formation while stimulating, to study selective plugging and diverting technology in water plugging, profile control and acidizing. A kind of temporary plugging which oil soluble resin JHY was studied with this equipment for the acidizing diversion affect and succeeded in Henan Oilfield.