The market price of carbon fiber which is considerably high, has limited its application as a value-added material. Lignin, a natural source that can be obtained from oil palm frond (OPF) is a promising precursor for carbon fiber production. This study aims to determine the feasibility of OPF lignin extracted under subcritical phenol conditions as a precursor for carbon fiber. The focus of this study is to determine the fundamental properties (ash content and volatile content) of the produced lignophenol produced based on the effect of reaction parameters such as temperature (260–300 C), reaction time (5–30 minutes), and solid loading (6 and 10 g). The results indicate that the lowest ash content and volatile content of 9.87% and 6.45% was obtained at 260 C, 5 minutes, and 6 g solid loading respectively. It can be further concluded that low reaction temperature as well as time and higher solid loading produced lignophenol with low ash and volatile content under subcritical phenol conditions.