Objective: Reasoning is thought to be the core component of general fluid intelligence. A high correlation has been reported between reasoning ability and working memory. There are studies showed that reasoning aging can be mediated by working memory, some researchers explain that working memory can affect the target maintenance in cognitive tasks, thus affect the performance of reasoning ability. However, the previous relevant study usually focused on the role of working memory capacity, while the other components of working memory which are important to target maintenance, such as attention switching and inhibition were rarely involved. What’ more, most of the previous studies chose college students as subjects, while the reasoning aging was not studied enough as an important area. In this study, the components of working memory system which are closely related to target maintenance __ working memory capacity, attention switching and inhibition were chosen as the indicators to examine the role of working memory in inductive reasoning aging. Methods: Totally 43 community-dwelling older adults, ranging in age from 75 to 95 years , and 74 college students ranging in age from 18 to 29 years were recruited in this study. All the participants took a battery of tests including Graphical Reasoning Test, Operation Working Memory Span Test, Task-switching Test and Stroop Test on computer. In the Graphical Reasoning test, the subjects were asked to find the target figure among five alternative choices according to a change in the rules between two given figures. In the Operation Working Memory Span Test, The participants were instructed to perform the calculation in their mind and remember the answer to each question, holding the entire set of answers in their memory until they were instructed to recall them in the same serial order that the equations had been presented. In the Task-switching test, a 2*2 grid was placed in the central part of the screen and there was a three-digit number in one field of the grid. When the number appeared in the two cells above, the subjects were asked to determine whether this number was odd. When the number appeared in the two cells below, the subjects were asked to determine whether the number was more than 500. In the Stroop test, The subjects were shown Chinese characters written in color, (e.g., “red” in green) and they were asked to determine the print color of the characters. Results: Correlation analysis results showed that working memory capacity, attention switching ability are significantly correlated to the inductive reasoning ability. Meanwhile, the same result was not observed between inhibition and reasoning ability, thus the indicator of inhibition was not included in the further analysis. The mediating effect analysis showed that: 1) There is significant mediating effect of working memory capacity between age and inductive reasoning ability, the effect size was 18%; 2) the mediating effect of attention switching is not significant; 3) The inhibition ability can’t enter into the mediating model. Conclusion: There is a significant mediating effect of working memory capacity between age and inductive reasoning.