The tight oil resource is extremely abundant in China, but the production and researches of tight oil is just at the beginning stage. There are great challenges in developping the tight reservoirs. Although small pore size and low permeability can greatly increase the development difficulty, spontaneous imbibition mostly resulted from the capillary pressure is a very important and useful way for tight oil production. In the laboratory experiments through the homemade imbibition apparatus and the effects of different parameters on the imbibition recovery factor was investigated. The results show that the imbibition recovery factor is significantly increased with the increasing of temperature. For rocks with similar parameters ,the recovery factor is increased as the formation water salinity decreases within a certain range. The recovery factor by imbibition varied due to the different boundary conditions. In addition, the curves show good normalization character after processing the data with dimensionless, which can be used to estimate the actual production efficiency of the field. Undoubtedly, the research is of great significance for effectively developing the tight oil reservoir.