Abstract: How do people use rules and examples in categorization? The authors studied this question by three experiments. Ss were 110 university students. After Ss learned the materials of categorization, they were asked to administer the transfer test in categorization. The categorizing strategy of Ss was investigated. In experiment 1，it was explored whether the subjects tended to use the rule-based categorization strategy after the category structure in Erickson and Kruchke’s experiment was changed so that the rule was more conspicuous. Contrary to experiment 1，it was examined whether the subjects would use the example-based categorization strategy mainly when they faced more complex category structure in experiment 2. In experiment 3，it was explored what kind of rule would be facilitated when more than one rule was suitable. The results showed that the subjects would use the rule-based categorization strategy when the rule was easy to grasp，and they would use the example-based categorization strategy when the task was harder. The subjects tended to choose the general rule than the concrete one，and the universal rule than the limitary one. These results suggested that the rule-based categorization strategy is chosen first in category learning，and that the example-based strategy would be used only when the rule is difficult to be extracted. The results also suggest that the general and the universal rules are more possible to be used when there are several rules available

Key words: rule-based categorization strategy, example-based categorization strategy, categorization