Using news articles in science instruction assists students in connecting science in school with science in life. Exploring the factors that influence students in forming value claims when they deal with various science news articles is of significance for developing scientific literacy and media literacy. Our research focused on using different reproduction/genetics news articles to study what stand-points and reasons seventh graders adopt when they read scientific news articles as well as how students' positions and argumentative reasoning were changed by small group discussion. The results indicated that more than 70% of seventh graders accepted the position presented in selected science news articles. The ”position before discussion” (p<.001) and ”group composition” (p<.05) significantly affected their position after group discussion. The structure of concept branches in the text of science news articles was another influencing factor. The research suggests that science teachers need to choose news materials carefully and develop pedagogies for cultivating students' critical literacy in reading media.