Constipation is a common problem which ordinarily refers to as persistent, difficult, infrequent, or seemingly incomplete defecation. It includes passage of unduly dry and hard feces, sluggish action of bowel, etc. The present study evaluated the efficacy of the extract of Perilla frutescens var. japonica leaf against the activated carbon induced constipation in ICR mice. Constipation in mice was induced by the oral administration of active carbon (10% activated carbon dissolved in 0.5% arabic gum water) while the control group mice received 0.5% arabic gum water only. Constipated mice were treated with 0.5 or 1.0 g/kg body weight/day of the Perilla frutescens var. japonica leaf extract for 9 days during which all the characteristics including the feeding characteristics as body weight, dietary and drinking water amount intake, as well as fecal properties, first black stool time, gastrointestinal transit and levels of serum biomarkers such as gastrin, motilin, substance P and somatostain all were monitored thoroughly. Treatment of constipated mice shows inhibited body weight loss, dietary intake loss, with increased intestinal motility speed, fecal volume, it also shortens the first black stool time, accelerated the serum levels in gastrin, motilin, substance P, decreased the serum level somatostain which inhibited Growth Hormone (GH). Especially the anti-constipation property shown by the extract of the herb at the intake level 1.0 g/kg body weight shows the best efficacy. The effect of the extract has comparative results with biscodyl, a standard laxative drug. These findings demonstrated that Perilla frutescens var. japonica leaf can be regarded as a natural preventive method of constipation medicine.