Lutein is found in two forms: free and ester form in nature. However, most lutein in nature is an ester form, esterified with fatty acid. Moreover, it is well known that the ester form is more stable than the free form. Currently, the free form produced by saponification from marigold oleoresin is distributed as lutein-fortified functional food. Numerous studies on the bioavailability of free and ester form have been conducted, but there are contrasting results as to which of them has better bioavailability. In this study, lutein diester was synthesized successfully in a solvent system from a lutein and a fatty acid via lipase-catalyzed esterification. The fatty acid as a substrate was prepared by saponification from perilla oil with α-linolenic acid of ca. 60%. The effects of variations in temperature, enzyme loading, and molar ratio were explored as a function of reaction time. The optimal temperature, enzyme loading, and molar ratio (lutein to fatty acid) were 50oC, 15% (based on the total weight of substrate), and 1:10, respectively. The maximum conversion of lutein diester was ca. 90% at the optimum condition.