Rendang is a typical Minangkabau cuisine in West Sumatra, which is usually made with beef and other protein resources such as Lokan, which contains amino acids L-leucine and L-isoleucine. It is made with coconut milk that produces oil during cooking. The oil can be substituted with Red Palm Oil Olein (RPOO), which contains nutrients essential for the body as antioxidants. This study aims to determine the effect of RPOO substitution in Lokan rendang on color properties, vitamin A content, antioxidant activity, and organoleptic. The experimental design in this research was a Completely Randomized Design (CRD) with one factor and five treatment levels. The treatment factor was RPOO substitution with 0, 25, 50, 75, and 100% Lokan rendang oil. The result showed that RPOO substitution significantly affected the antioxidant and organoleptic activity (taste, aroma, and overall) of rendang Lokan. The greater the substituted RPOO, the greater the vitamin A content in Lokan rendang.