The purpose of this study is to find out the effect on academic achievement and science-related affective domain of elementary students though science journal writing about the units of Science textbook of the first semester of the sixth grade. The results indicate that science-journal writing has influenced the students positively in the academic achievement of a lower group's academic achievements, in science related attitudes, 'voluntariness' and 'cooperation', in science learning motives, 'self-satisfaction for science', 'superficial strategies for science', and 'expectation for science', in fear level for science subjects, its lower fear class, 'experiment performance'. A middle group was revealed to have more positive improvement in 'cooperation' and 'perseverance', both of which were lower categories of science related attitudes, and as subgrade of science learning motives, 'self-efficiency for science' and 'expectation for science' stood out. For fear level for science subjects, the lower group gained distinctive results from 'science evaluation'.