This study is to demonstrate the impact of different teaching strategies on the learning performance of environmental education using quantitative methods. Students learned about resource recycling and classification through an instructional website based on the teaching tool of WebQuest. There were 103 sixth-grade students participating in this study and broken down into three groups: traditional instruction, traditional instruction with WebQuest and WebQuest instruction with outdoors. The major contribution of this study is the introduction of WebQuest into the outdoor instruction. The results of this study show that using WebQuest in outdoor instruction influences students' learning performance positively. Two other interesting results are: (1) when WebQuest was used in real situations, students could acquire more knowledge and experiences, and (2) in the learning activity of the experiment, the students accomplished different learning tasks and expressed their own opinions and perspectives, which could foster their critical thinking skills. On the other hands, the students in outdoor situation could be positive to participate in learning activity; furthermore, they could ponder the learning contents by observing the real context and then they began to classify/categorize the resources. These findings will contribute to the development of teaching and learning for government, schools and teachers; for instance, teachers act as assistants or tutors and provide students with others public network resources, including PDAs, smartphones, tablet personal computers or the Internet, to improve their learning in outdoor learning environments, such as campus, museums or zoos.