The aim of this research was to determine the effect of boiling time on vitamin C, antioxidant activity, reduction sugar, pH and sensory properties (tastes and aroma) of Singapore cherry (Muntingia calabura L.) syrup. The experimental design used was Completely Randomized Design (CRD) one factor (boiling time) consist of five treatments: P1 (20 minute), P2 (30 minute), P3 (40 minute), P4 (50 minute), P5 (60 minute). The observed parameters were vitamin C, antioxidant activity, reduction sugar, pH and sensory properties (tastes and aroma with hedonic and scoring test). The data were analyzed using analysis of variance at 5% confident level with Co-Stat software. The significant data were analyzed using Honestly Significant Differences (HSD) test. The result showed that boiling time gave a significant effect on pH, vitamin C, antioxidant activity and reduction sugar but didn't significant on sensory properties (tastes and aromas). The best treatment was boiling time for 20 minutes that resulted in the highest value of vitamin C (28.09 mg/100 g material) and antioxidant activity (51.79%). Meanwhile the reduction sugar was 7.95%, pH 4.28, the taste was rather sweet and the aroma was rather specific of Singapore cherry.