This study is a development research, which uses ADDIE development model. The study was conducted in the even semester of the academic year 2019/2020. The authentic assessment instruments developed consist of cognitive and psychomotor assessment instruments for measuring the students’ science literacy skills in 10th grade on Environmental Change material. Indicators of scientific literacy refer to indicators developed by Gormally (2012). Measurement aspect were the validity by the expert appraisal and empirical validity test, difficulty level and practicability of instrument. The results of study showed the authentic assessment instruments that had been developed were proper to use with validity value 4.43. Empirical validity data for multiple choice were analysed using point biserial correlation. Result showed 76% in valid category with reliability value 0,82. For essay and psychomotor assessment showed 100% in valid category. The reliability value for essay is in the reliable category with value 0,62. Psychomotor assessment with reliability value 0,89. Difficulty index of assessment instrument in cognitive domain for multiple choice were 24 % in difficult level, 44 % in moderate level and 32 % in easy level, meanwhile for essay 40 % difficulty index in moderate level and 60 % in easy level. Result of data analysis for and practicality of authentic assessment instruments based on scientific literacy were in practically category.