Dyslexia is a learning disability. Many educational researches discuss how to remedy dyslexia and provide strategies, but only a few studies explored dyslexic students’ electroencephalogram (EEG). Therefore, this study aims to explore EEG coherence of 16 element school students while they were reading or writing. In these 16 students, 8 are with dyslexia and others are not. They are divided into 2 groups. All students are asked to read or write some materials which are picked and codified from Mandarin textbooks or workbooks that they have learned last semester. During reading and writing, their EEG were recorded. The results show that the scores of reading and writing test, or the coherence of θ and β bands in EEG all had the significant differences between dyslexia and normal students.