 This study investigates the thermal characteristics of FLAX fiber reinforced phenolic resin composites, FRPCs, and basalt fiber reinforced phenolic resin composites, BRPCs, with different volume percentages of chemically treated FLAX and basalt fibers using DSC, TGA, and SEM techniques. The results show that FRPC and BRPC samples reinforced with 6% VF of the respective fibers have better, thermal stability than other volume percentages due to their relatively high glass transition temperature, TG. This article was authored by Ayashok Kumar, Ayurul Jayakumar, and M Prakash.