HOTS is an ability to transfer, connect one material with another, possess information and solve problems derived from the information in a creative and critical manner. Higher Order Thinking Skill (HOTS) are abilities that must be possessed by students in facing global competition in the 21st century industrial revolution 4.0 in accordence with the 2013 curriculum. This study aims to produce  a test instrument for higher order thinking skill (HOTS) in chemical equilibrium and determine the level of validity and its reliability. This type of research is research and development (R&D) and uses the research model that has been developed by treagust (1988). The results showed that the value of the validity of the content instrument test was 1 and the validity of the construct instrument was 95% in the material aspect, 94% in the presentation aspect, 96% in the language aspect, and 08% on the additional rules. The instrument reliability tes coefficient is 0,85 for the question (fisrt tier) and 0,89 for the reason (second tier).