Abstract: Two experiments were conducted to explore the effects of hypertext structure, task type and navigation on information searching in network. In Experiment 1, 2（hypertext structure: hierarchical vs mixed）×2（task type: specific vs relational）within-subject factorial design was used to examine the effects of structure and task type on searching performance in hypertext information. Based on the Experiment 1, 2（hypertext structure: hierarchical vs mixed）×2 （navigation: with map vs without map）within-subject factorial design was employed to consider the effects of structure and navigation on searching performance in the relational task in Experiment 2. It was found that:（1）Hypertext structure and task type interactively influenced on searching performance. Mixed was better than hierarchical in the relational task, but not in the specific task.（2）Navigation improved searching behavior, especially for hierarchical hypertext.（3）There was somewhat similar among subjective indexes（time estimation, subjective satisfaction rating）and objective behavior responses（searching time, accuracy, total number of nodes visited and repeatedly visited）.

Key words: hierarchical/mixed structure, navigation map, specific/relational task