The main purpose of this study was to enhance student understanding of the scientific concepts of chemical reaction rate. Forty-four grade 11 students were the target group. The treatment tools were seven learning plans of 5E inquiry incorporated with an analogy learning approach during 15 hours of class time. In each learning plan, the students (1) addressed a scientific question regarding chemical reaction rate, (2) explored evidence to answer the question by carrying out a corresponding experiment, (3) drew explanations from collected evidence to answer the question, (4) elaborated their understanding by studying the given analogy and the target, and (5) evaluated their conceptual understandings by creating their own analogy and identifying similarities and differences of their analogies and the targets. The data collecting tool was a conceptual test of chemical reaction rate, consisting of 30 two-tier three-choice questions. The normalized learning gain for the whole conceptual test was at the medium gain level (0.64). The dependent samples t-test analysis indicated that the post-conceptual test score (mean 45.32, SD 6.46) was statistically higher than the pre-test score (mean 19.70, SD 3.10), but was statistically lower than the retention test score (mean 48.03, SD 9.04) at the significance level of 0.05. In the pre-conceptual test, the percentages of students in the good-, alternative-, and misconception categories were 13.69, 38.45, and 47.86, respectively. In the post-conceptual test, the percentages of students in these categories were 64.72, 24.6, and 10.63, respectively. This finding indicates that this implementation was an effective means to enhance and retain students' conceptual understanding of chemical reaction rate.