In the era of computer and communication technologies, fostering students' high-level thinking abilities has become an important educational objective. Engaging students in web information searching to answer a series of questions related to a target issue has been recognized as a helpful approach for promoting students' thinking processes. In this study, a contextual learning approach is employed in web information searching activities to improve students' learning achievement, attitudes and critical thinking ability. The participants were divided into an experimental group, which was guided to use Internet resources to complete problem-based learning tasks with the contextual learning approach, and a control group, which learned with the conventional web information searching approach that situated students in a pure web information searching environment to answer questions for the issue to be investigated. From the experimental results, it was found that the experimental group exhibited significantly better learning attitudes, learning achievement, and better critical thinking than the control group, suggesting the effectiveness of the integrated contextual and web information searching approach in terms of helping students use Internet resources to investigate the target issue in depth.