Problem statement: The object of this research aimed to investigate a nd compare effects of learning environmental education by wises of two ap proaches: The 5 E-Learning cycle with met cognitive techniques and the teacher's handbooks, o n learning achievement, basic science process skills and critical thinking of 75 Mathayomsuksa 3 (grade 9) students with different learning achievements. Approach: They were assigned to an experimental group with 3 8 students who learned using the 5 E-Learning cycle with met cognitive tec hniques and a control group with 37 students who learned using the teacher's handbook approach. Inst ruments used in the study included (1) 6 plans of learning organization using the 5 E-Learning cycle with 3 met cognitive techniques: Intelligibility, plausibility and wide applicability, 6 plans of lea rning organization using the teacher's handbook, approach; each plan for 3 h of learning in each wee k; (2) the learning achievement test with 40 item; (3) the test on basic science process skills with 8 subclass and 40 items and (4) the critical thinkin g test with 5 subclass and 54 items. The data were analyze d by the uses of a percentage, mean, a standard deviation, the paired t-test and the f-test (two-wa y MANCOVA). Results: The whole students, The high achievers and the low achievers in the experim ental group showed gains in learning achievement, basic science process skills in general and in 3-6 subclass and critical thinking in general and in 4- 5 subclass from before learning at the 0.05 level of significance. The experimental group indicated more learning achievement, basic science process skills in general and in 2 subclass: Process skills in gen eral and in 2 subclass: Measuring and predicting and cri tical thinking in general and in 1 subclass: interpretation, than the control group at the 0.05 level of significance. The high achievers shoed onl y higher basic science process skill in general and i n 3 subclass: Using space-time relationship, classifying and predicting, more than the low achie ves at the 0.05 level of significance. The statisti cal interactions of learning achievement with learning model on learning achievement and critical thinking were not found to be significant. Whereas, the inte raction of these two variables on basic science process skills in general and in 3 subclass: Measur ing, classifying and predicting were found to be significant at the 0.05 level. Concussion/Recommendations: The 5 E-Leaning cycle with met cognitive techniques could develop efficiently lear ning achievement, basic science process skills and critical thinking of the students. The teachers, th erefore, should be encourage and supported to implement this approach in teaching and learning en vironmental education in all grade levels.