: The Role of Interior Design Toward Users's Satisfaction (Study on The Library of SMKN 4 Malang). The library need to increase their services by providing the needed books and creating attractive, interesting, comfortable, and supportive library building. To increase the function of school library, librarians of SMKN 4 Malang built library building by observing its interior design. This interior design includes 5 elements that really important related to users's satisfaction, they are layout, color scheme, lighting, air circulation, and acoustic (sound system). Source of data used comes from the questionnaires and total sample of 100 respondents. The research result of those 5 indicators which has role toward users's satisfaction show that t test indicators role of interior design toward users's satisfaction is lighting, ventilation dan acoustic (sound system). F test shows that there is role of interior design toward users's satisfaction is air circulation.