The present disclosure provides an extract of Citrus reticulata fruitlet, and a use of the extract of Citrus reticulata fruitlet for reducing lipid accumulation. The extract of Citrus reticulata fruitlet includes tetramethylisoscutellarein, and the tetramethylisoscutellarein has the following formula (I):本發明提供一種柑橘幼果的萃取物及其用於降低脂肪堆積的用途。本發明的柑橘幼果萃取物包含四甲基異高山黃芩素,其中四甲基異高山黃芩素具有下列化學式(I):