Instructing students to read science books is appropriate for the science career education in secondary education and an after-reading activity is also crucial in the reading education. Studies on reading education or after-reading activities were performed mainly in the areas of language or sociology for elementary students. In addition, many previous studies could not distinguish the effect of reading and after-reading activities. In order to investigate the effect of an after-reading activity, this research conducted a systematic study in which both the experimental group and control group performed the reading activity, while only the experimental group performed the after-reading activity. In this study an after-reading activity program of science books was developed and the effect of the program was investigated. The after-reading activities reported in previous studies were analyzed, and the after-reading activity program for the 7th grade science class was developed. The after-reading activity program consists of the recommended books, the reading materials and the after-reading activities. Four male/female classes were alloted as experimental groups and control groups and both groups performed the activity of reading science books. The after-reading activity was applied in the experimental group, and the control group performed a problem solving activity. Results showed that there was no difference in the achievement test scores of the two groups. In the science-related attitude test, the interaction effect was significant by treatment and gender. The female students showed higher science-related attitude (the social meaning of science, the acceptance of scientific attitude, and the interest in jobs in science) in the experimental group than those in the control group. This result shows the after-reading activity can be used in science career education for middle school female students. The perceptions on the after-reading activity program were surveyed in the experimental group. There was an after-reading activity which was helpful to understand the content of the science book, even though the activity was difficult to students. The science educator should pay more attention and use the after-reading activity.