This research aimed to produce statistics and probability teaching kit for grade X students of Senior High School in 2nd semester with guided discovery learning consist of lesson plans, student worksheets, and assessment instruments which valid, practical, and effective. The developing model in this research was 4D model consist of define, design, develop, and disseminate. Validity and practicality were analyzed by converting the actual scores obtained into five scales of qualitative data. Effectiveness analyzed by determining the percentage of students' completeness in a test and in the questionnaires. Validation result shows that the lesson plans have good category, the student worksheet and the assessment instrument have very good categories. The result of the application shows that the statistics application was 94,12% than the probability application was 84,29%. Based on the test and questionnaires result, the teaching kit was in effective term