The objective of research is to improve the story competency using series picture media in the III mild mental retarded graders of SLB – C Shanti Yoga Klaten in the school Year of 2008/2009. This study belongs to a classroom action research. The subject of research Was the III mental retarded graders of SLB C Shanti Yoga Klaten consisting of 6 students. Technique of collecting data used was test and observation. Technique of analyzing data used was descriptive comparative one. The implementation of reaserch involved several stages : planning, acting, Observing and reflecting starting from the prior competency, cycles, 1 and 2 actions as well finding weakness, benefit and improvement. Considering the result of research it can be concluded that the series picture media can improve the story writing competency of III mild mental retarded graders of SLB – C Shanty Yoga Klaten. Year of 2008/2009.