Retrival practice can enhance later retention more than additional study when review the material, this is the testing effect. The current research adopted low-related noun word pairs as the material in order to discuss the mechanism of the testing effect：Whether the testing effect depends on the process or the content? Experiment 1 used 2（review conditions：test, restudy）×3（testing intervals：5min, 2day and 1week）design to explore the interval of the testing effect. We needed to find a right interval for the testing effect because what we wanted to make sure is that the testing effect would depend on the process of test or the content during testing. The review conditions was between-subjects factor, the testing intervals was the within-subjects factor. The results: the testing effect did not appear under the 5min and 2day conditions, but it appeared under the 1week interval. It was visible that 1week was the most sensitive testing interval. According to the results of the Experiment 1, Experiment 2 was carried out under the 1week interval to find that the testing effect depends on he process or the content. Used 2（review conditions：test, restudy）×3（testing condition：A→B、A←B）design , and these two factors were both between-subjects, we studied the mechanism of testing effect. What we hypothesized was: If the testing effect depends on the content, the testing effect should be different under the “A→B” and “A←B” testing conditions; If the testing effect depends on the process, the testing effect should have no difference under the “A→B” and “A←B” testing conditions. The results of this experiment were: there is no difference of testing effect between the condition of “A→B” and “A←B”. That meant the testing effect depends on the process. The conclusions of this study are: the proper interval of the testing effect for the 11 years old participants is 1week; under this study condition，the testing effect depends on the process, not the content. Using ‘A→B’and ‘A←B’ ways during retrieving is an effective way to separate the process depended of testing effect from content depended.