Environmental education has recently received much more attention than before among elementary school students' science learning in Taiwan. The major purpose of this study is to explore the learning outcomes on environmental education for 5th graders in Taipei. A quasi-experimental design with a single group was used in this study. Students in the experimental group (N = 24) undertook five weeks of environmental education activities and a field trip to Elephant Mountain in rural Taipei. Three research instruments were used in this study, including an environmental education achievement test, an attitude toward environmental education scale, and an attitude toward environmental action skills. The results were analyzed using a t-test. The results of this study include: (1) the results of the environmental education achievement test showed that in the post-test the students obtained higher scores than in the pre-test (t = 7.47, p < 0.001); (2) the results of the attitude toward environmental education scale showed that students in the post-test achieved higher scores than in the pre-test (t = 4.10, p < 0.001), and (3) in the attitude toward environmental action skills students in the post-test achieved higher scores than in the pre-test (t = 3.63, p < 0.01). Therefore, it can be concluded that environmental education activities and the field trip are effective for 5th Graders' environmental learning.