Pati aren berasal dari empulur batang tanaman aren (Arenga pinnata Merr.). Pada penelitian ini telah dilakukan asilasi pati aren dengan cara mencampur pati aren dengan larutan asam stearat 7% dan 9% dalam etanol 96% pada suhu 50oC selama 12 jam. Selanjutnya terhadap hasil asilasi dilakukan uji karakteristik fisika, kimia dan fungsional kemudian diaplikasikan sebagai salut film tablet. Data percobaan menunjukkan terjadi ikatan ester antara gugus hidroksil (OH) pada pati dengan gugus stearat yang ditandai dengan terbentuknya gugus CO karbonil pada bilangan gelombang 1700-1725 cm-1 yang menghasilkan pati aren stearat (PAS). Kekuatan gel dan daya adhesi meningkat secara bermakna. Aplikasi PAS pada salut film mendekati kualitas salut film hidroksilpropilmetilselulosa (HPMC).Aren starch are obtained from aren stalk (Arenga pinnata Merr.). In this study acylation of aren starch had done by mixing aren starch with 7% and 9% stearic acid solution in ethanol 96% with temperature 50oC for 12 hours. The result of acylation are tested for the physics, chemical and functional characteristics and then applied as a film coating tablet. The experimental data showed that the ester binding are occurs between hydroxyl groups (OH) of starch with stearic groups which marked by the existances of CO carbonyl at wavelength 1700 - 1725 cm-1 which produce aren starch of stearic (ASS). Gel strength and adhesion energy significantly increase. The application of ASS as film coating are close enough with the quality hydroxypropilmethylcellulose (HPMC) as film coating.