For the trend of reviewing the effects of writing intervention research, this present study reviewed 13 earlier studies (N = 40) on single subject design writing instruction for students with learning disabilities by conducting a meta-analysis. In terms of composition quality, the average PND at posttest was 92.17% and the average PND at maintain posttest was 89.14%. In terms of length, the average PND at posttest was 74.58%, and the average PND at maintain posttest was 74.58%. Besides, the Kruskal-Wallis procedure revealed no statistically significant differences in dependent variables regardless of education level and intervention type variables.