Background: Thalassia hemprichii have reported containing antioxidant effects. However, information on other biological activities relating to the anti-wrinkle properties is limited. The free radical scavenging activity and enzyme inhibitory activity of the plant extracts investigated that they can help restore skin elasticity and thereby slow the wrinkling process. Objective: To evaluate in-vitro antioxidant and anti-collagenase activity of T. hemprichii as a potent ingredient for anti-wrinkle cosmetic. Methods: T. hemprichii was extracted with ethanol 100% (E1) 75% (E2) and ethanol 50% (E3) using maceration extraction method for 24 h, thrice. The extract was examined for total phenolic content, antioxidant activity compared with vitamin C, and the best extract was tested for the inhibitory activity of collagenase. Results: The total phenolic content of T. hempricii extract was 0,525 ± 0,016 mg GAE/100 g extract (E1) 0,538 ± 0,006 mg GAE/100 g extract (E2) and 0,558 ± 0,090 mg GAE/100 g extract (E3) respectively. The antioxidant activity (% inhibition) of the extract was 38,035 ± 0,252 % (E1), 52,502 ± 6,225 % (E2) and 57,261 ± 0,505 % (E3). Ascorbic acid as a positive control of antioxidant activity showed much higher % inhibition than the sample with 78,055 ± 0,756 %. As the best extract from antioxidant activity, E2 and E3 have inhibited collagenase activity with 51,809 ± 0,164 % and 52,212 ± 0,735 % at 20μg/mL respectively. Conclusion: In general the (T. hempricii) extract can be used as a potential active ingradient for anti-wrinkles cosmetic.