Tujuan penelitian ini yaitu untuk mengetahui reaksi amidasi asam sinamat dengan N, N-dietil amina menggunakan katalisator asam borat dan mengetahui aktivitas antikolesterol dari produk senyawa hasil amidasi. Reaksi amidasi asam sinamat dengan N, N-dietil amina menggunakan variasi konsentrasi (% mol) asam borat sebagai katalis yaitu 5, 10, 15, 20 dan 25%. Hasil reaksi amidasi dikarakteristik menggunakan FT-IR, 1H-NMR dan 13C-NMR. Aktivitas antikolesterol dianalisis menggunakan metode Liebermann-Burchard. Hasil penelitian menunjukkan bahwa produk amidasi asam sinamat yaitu 20,47%, 22,99%; 23,37%; 26,77% dan 30,28% untuk variasi mol asam borat secara berturut-turut 5%, 10, 15, 20 dan 25%. Hasil karakterisasi dengan FT-IR, 1H-NMR dan 13C-NMR menunjukkan bahwa produk hasil amidasi berupa senyawa N, N-dietil sinamamida. Senyawa hasil amidasi mampu menurunkan kadar kolesterol sebesar 5,24%; 27,18% dan 13,22% dengan konsentrasi senyawa berturut-turut sebesar 50, 100, dan 150 ppm. Semakin besar persen mol katalisator asam borat yang digunakan, semakin besar senyawa hasil amidasi yang diperoleh. Produk hasil amidasi yang diperoleh yaitu senyawa N, N-dietil sinamamida yang berpotensi sebagai antikolesterol dengan aktivitas optimum pada konsentrasi 100 ppm. Kata kunci: Amidasi; antikolesterol; asam borat; asam sinamat; sinamamida Mole Variation of Concentration Boric Acid in The Amidation Reaction of Cinnamic Acid and Its Potential as Anticholesterol ABSTRACT The aims of this study to determine the amidation reaction of cinnamic acid with N, N-diethylamine using a boric acid catalyst and to determine the anticholesterol activity of the amidation product. The amidation reaction of cinnamic acid with N, N-diethyl amine using various concentration (% mole) of boric acid as a catalyst, namely 5, 10, 15, 20, and 25%. The amidation reaction results were characterized using FT-IR, 1H-NMR, and 13C-NMR. The anticholesterol activity was analyzed using the Liebermann-Burchard method. The results showed that the amidation products of cinnamic acid were 20.47%, 22.99%; 23.37%; 26.77%, and 30.28% for variations in moles of boric acid 5%, 10, 15, 20, and 25%, respectively. The results of characterization using FT-IR, 1H-NMR and 13C-NMR showed that the amidation product was N, N-diethyl cinnamamide. The compound resulting from the amidation was able to reduce cholesterol levels by 5.24%; 27.18%, and 13.22% with compound concentrations of 50, 100, and 150 ppm, respectively. The greater the mole percent of boric acid catalyst used, the greater the amidation product obtained. The amidation product formed is N, N-diethyl cinnamamide which has the potential as an anticholesterol with optimum activity at a concentration of 100 ppm. Keywords: Amidation; anticholesterol; boric acid; cinnamic acid; cinnamamide