Citrus suhuiensis cv. limau langkat (L) and Citrus suhuiensis cv. limau madu (M) are both important cultivars that have been cultivated widely in Malaysia. In this study, both cultivars were mixed into 5 different formulations and undergone heat treatment using water bath at 90℃ for 30 s. The objectives of this study were to compare the physicochemical and organoleptic properties as well as antioxidant activities of fruit juice before and after heat treatment. Physicochemical analysis such as color measurement, pH determination, total soluble solid and titratable acidity were determined. Phytochemical analysis involving ascorbic acid content, total phenolic content and DPPH free radical scavenging activity were also assessed. No significant difference were found on the physicochemical parameters and ascorbic acid content in general after heat treatment was subjected to the fruit juice. The heat treatment applied had increased the antioxidant activity of sample made with 100% L significantly (p<0.05) with 8.68% inhibition using DPPH assay as well as significantly increasing (p<0.05) total phenolic content of sample 10% L + 90% M (19.05 mg GAE/ mL). Sensory evaluation had shown that sample 10% L + 90% M was the most preferred in terms of color, aroma, sweetness, sourness and having an overall acceptability of 5.83.