This paper analyzes interactions between teachers and students with developmental disabilities in a special education school in China, which is still the main educational placement for the disabled in China. Video observation data collected from six students in second grade and one teacher, were coded by an improved Flanders Interaction Analysis System (iFIAS). Results indicate that the teacher played the dominant role in the class while her/his instruction was student-oriented, several evidence-based strategies were used to motivate students' engagement, including questioning, timely feedback, reinforcement, game teaching, students' self-determination. Few peer interactions happened due to homogeneous grouping. Besides, the frequency of interaction patterns between teachers and students with developmental disabilities (DD) of different learning ability was similar while the interaction patterns were different. There were more non-academic interactions between the teacher and students with most serious disabilities in the class than others, while there existed more cognitive extension-partial and full interactions between teachers and students with least serious disabilities in the class than others. The results shed light on how teachers interact with students who have DD, and how interactions can be differentially delivered to students with DD of various learning abilities.