For most of students with autism spectrum disorders (ASD) and Williams syndrome (WS), a rare genetic neurodevelopmental disorder, are known to have intellectual disabilities (ID). Students with ID often show the difficulties in reading. Especially, they are difficult to acquire the equivalence relations among pictures, written letters, and sounds and to have fluent eye movement during reading. Previous research suggested that a student with autism acquired Kanji reading skills by using stimulus pairing training. However, for acquiring word reading skills, new training which facilitates the fluent eye movement is necessary and we developed sequential stimulus pairing training. In the present study, we examined the acquisition of word reading skills through sequential stimulus pairing training for three students with ID who were also diagnosed as WS and three students with ID who were not diagnosed with WS. In a trial, each letters, the word, spoken sound, and picture were presented sequentially. With 6 students, result indicated that they could acquire the word reading skills, and also showed the improvement of their eye movement in reading. The result suggested sequential stimulus pairing training is effective to acquire both equivalence relations and fluent eye movement for wide range of students with ID.