Results: 32 patients were included in the study with the ratio of male / female patients was 1/1, the mean age of patients was 56.78 ± 18.6 years old (ranges 18 to 88 years old), the typical clinical symptoms were 90.6% abdominal pain, 53.1% loose stool 3 - 4 times per day more than usual, 43.8% bloody stool not continuously less than half the time, the paraclinical characteristics included 43.75% normal hemoglobin, 65.6% high white blood cell count, standard endoscopic features of ulcerative colitis seen 65.6% proctitis and 46.9% stage 1 (erythema, decreased vascular pattern, mild friability), the induction treatment result with Pentasa was 81.2% achieved remission.