en ترکیبات طبیعی Natural products پژوهشي Original Research <em>Sterculia populifolia</em> is commonly used as the ingredient of traditional herb in Timor Island, East Nusa Tenggara, Indonesia. It contains flavonoid which roles as antioxidant. This flavonoid can be sunblock due to the existence of chromophore which commonly gives color to plants. This study aimed to determine the activity of antioxidants and sunblock through the value of <em>Sun Protection Factor</em> (SPF) from <em>Sterculia populifolia </em>extract-based cream and cream preparation extract. This cream was formulated into four formulas; extract concentrate 0% (F0), 1% (F1), 3% (F2) and 5% (F3). The result showed that the whole formula of cream preparation filled the physical stability parameter. F3 cream had <em>IC₅₀</em> 79.179 ppm value while SPF had 5.6 value higher than F1 and F2. The smaller the <em>IC</em>₅₀ value, the bigger antioxidant activity and SPF increased. Sterculia Populifolia Dc, Sun Protector Factor, Antioxidant activity 20 26 http://pbr.mazums.ac.ir/browse.php?a_code=A-10-386-1&slc_lang=en&sid=1 Nur Khairi Nur Khairi khairinur10@gmail.com 10031947532846001998 10031947532846001998 Yes Departement of Pharmaceutics, Faculty of Pharmacy, Sekolah Tinggi Ilmu Farmasi Makassar, Indonesia Suryani As'ad Suryani As'ad asadsuryani8@gmail.com 10031947532846001999 10031947532846001999 No Departement of Nutrition Faculty of Medicine, Hasanuddin University, Makassar, Indonesia Khaeruddin Djawat Khaeruddin Djawat khaeruddindjawat@gmail.com 10031947532846002000 10031947532846002000 No Departement of Dermatovenereology, Faculty of Medicine, Hasanuddin University, Makassar, Indonesia Gemini Alam Gemini Alam geminialam911@gmail.com 10031947532846002001 10031947532846002001 No Departement of Pharmacognosy, Faculty of Pharmacy, Hasanuddin University, Makassar, Indonesia