Gastric ulcers are caused by excessive gastric acid secretion, alcohol, and long-term use of nonsteroidal anti-inflammatory drugs (NSAIDs). Aspirin is one of the NSAIDS that can induce peptic ulcers. Traditional medicines that have been proven to have gastroprotective activity is Andrographis paniculata (APAC). The purpose of this study is to assess the antioxidant activity and gastroprotective effect of purified extract of APAC. The herbal treatment was given for 7 days, and on the eighth day, all groups except the negative control (Na CMC 0.5%) were given 1000mg/kgBW of aspirin. Six hours later, the rats were sacrificed and opened for macroscopic examination, pH gastric juice value, the volume of gastric value, ulcer index, and inhibition percentage. Antioxidant studies using 2,2-diphenyl-1-picrylhydrazyl (DPPH) showed that APAC has strong antioxidant activity with IC50 value = 64.54. APAC could reduce the occurrence of gastric ulcers by decreasing gastric pH, ulcer index, and increasing inhibition percentage (P=0.000<0.05). Andrographis paniculata has gastroprotective properties associated with antioxidant activity.