Antiulcerogenic effect of the alcoholic (ALJP) and aqueous (AQJP) extracts of the whole plant of Justicia prostrata was studied in aspirin+pylorus ligated rat models and analysed for gastric volume, ulcer index, free and total acidity. Biochemical parameters like total proteins, total hexoses, hexosamine, fucose and sialic acid were also estimated. Both extracts (ALJP and AQJP) significantly reduced both the gastric volume and the acidity of gastric juice. It also significantly promoted gastric mucus secretion by increasing total carbohydrates and decreasing the protein concentration in aspirin+ pylorus ligated rats. The results suggest that both the extracts (ALJP and AQJP) possess antiulcer activity, whereas AQJP is more effective when compared with ALJP in aspirin+pylorus ligated rat models. The results were compared with the standard drug Rantidine, a H2 receptor antagonist.