Students worksheets based inquiry training model on colligative properties of solution  is a students guide to do scientific experiments so it can help students to understand colligative properties of solution. The purpose of this research is producing valid students worksheets to support the learning of colligative properties of solution using inquiry training learning model. Students worksheets development using ADDIE (Analyze, Design, Development, Implementation, and Evaluation) design. Students worksheets were implemented in grade XI of Trensains Senior High School Tebuireng Jombang by using research One Group Pretest-Posttest Design. The data collection techniques using validation. The analysis technical of data using descriptive analysis. Students worksheets validity includes contents validity and construct validity. Result of validation from three validator are (1) the students worksheets are valid in contents, it was shown by the validation average score of each aspect are: aspect1=4,0; aspect 2=3,33; aspect 3=4,0; and aspect 4=3,33 and (2) the students worksheets are valid in construct, it was shown by  the validation average score of each aspect are: aspect1=3,67; aspect 2=3,33; aspect 3=3,67; aspect 4=3,67; and aspect 5=3,33. The conclusion of this research is the student worksheet that has been made has fulfilled the valid criteria either contents or constructs, so the worksheet can be used in the learning process to help the students understand the material.