This paper focuses on investigating the effectiveness of the professional learning community (PLC) on student teachers' curriculum development skills, as well as the effectiveness of the professional learning community (PLC) on Thai L1 young students' reading comprehension. The instruments utilized for the study include the following: a professional learning community activity, learning management for developing students' reading comprehension, a test for student teachers' curriculum design skills, and a test for students' reading comprehension. The data were analyzed using percentage, mean score, standard deviation, a pair samples-test, and the effectiveness index, with the criterion of 80%. The results of the study indicate that the professional learning community (PLC) positively affected student teachers' curriculum design skills as the effectiveness of the method was 94.57/94.96 (E1 94.57/E2 = 94.96), reaching the criterion of 80. The professional learning community (PLC) was also beneficial in developing students' reading comprehension. The effectiveness index of the method was 83.54/85.77 (E1 = 83.54/E2 = 85.77), reaching the criteria set at 80. The results of the study therefore suggest the benefits of the professional learning community (PLC) for both teacher education and student skill development.