Background: We adopted a theoretical framework that the acquisition of a scientific concept comprises the development of connections among conceptual elements associated with a scientific term within a mental semantic network. Given this framework, the hypothesis that the surrounding words connected with a scientific term are relevant to the comprehension of that concept was considered. Purpose: Students' mental semantic networks through a word association test were examined, which experimentally revealed whether the quantitative and qualitative connection of scientific terminology with conceptual elements is related to concept comprehension. Sample: We selected five scientific concept words -- 'force', 'motion', 'speed', 'mass' and 'gravity' -- and investigated the mental semantic networks of 1,189 students regarding these five words. Design and Methods: We prepared a word association test and a concept comprehension test for the 5 words; further, we asked the subjects to write 10 words that are associated with each stimulus word. The concept comprehension test was conducted with multiple-choice questions, comprising 6 questions for each stimulus word. Additionally, this study examined the relation between the concept comprehension and word association test scores. Results: All the values extracted from the word association test were significantly correlated with concept comprehension. Specifically, the concept comprehension score was higher when the relation between the scientific terminology and words that form the scientific context as well as the scientific terminology and other scientific terminologies were more closely and frequently connected in the mental semantic network. Conclusion: This study experimentally verifies that word-level connections are related to concept comprehension in students' mental semantic networks. This shows that a cognitive linguistic approach to the development and modification of students' mental semantic networks can be applied effectively in science education. Moreover, it indicates the possibility of adopting linguistic strategies in science education for the formation and modification of scientific concepts.