Mathematical communication ability is one of the abilities that must be possessed by students in 21st century learning. Worksheets of students who have not yet integrated mathematical abilities will hinder the achievement of learning objectives. Problem based learning is a model that can improve mathematical communication skills. This study aims to design mathematics student worksheets of problem based learning models to improve mathematical communication skills. This research is a type of development research with the ADDIE model. This research focused on the design stage of ADDIE model. The subject of this study consisted of teachers and students of MTs Class VIII, Seleman, Indonesia. The instrument of data collection consists of observation guidelines, interview guidelines and documentation sheets. Observation guidelines are used for the characteristics of students' mathematical communication. The interview guide used to retrieve student characteristics data from the teacher's perspective during the learning process. The documentation sheet manual used to view curriculum implementation data that apply in the school. The data were analyzed by using quantitative data with the provisions of the Likert scale. Producing design products in the form of student worksheets as learning media, the quality of the design is "very good" with a score of 4.36. An average score of 4.08 by filling in the LKS design, 4.33 LKS design languages and 4.5 technical aspects. This study resulted in the design of student worksheets of problem based learning models according to the needs of students. Student worksheets are designed to improve students' mathematical communication skills.The results of the study show that the quality of the design products produced based on the validity and the student worksheets met the criteria well. This research can be expanded at the stage of developing, implementing and evaluating.