Abstract: AIM　To observe the effects of DL111-IT on decidual cells, content of PGE₂ and PGF_2α, and uterine contractibility of pregnant rats. METHODS　HE stain, radioimmunoassay and uterine contractility in vitro were used to estimate histologitic changes in decidual cells, PGE₂ and PGF_2α concentration in uterus and serum and the uterine contrability of pregnant rats, respectively. RESULTS　After im DL111-IT ×5　d, the PGE2 and PGF2α contents in uterus of pregnant rats increased 118.2% and 213.7%, respectively, and those in serum were increased 74.3% and 227.7%, respectively. Edema, degeneration and solvate at decidual cells with indefinite nuclei were observed in pregnant rats treated with DL111-IT for 3～5 days. DL111-IT strengthened the uterine contraction of pregnant rats and the uterine response to oxytocin and misoprostol in vitro. CONCLUSION　DL111-IT damaged the decidual cells, incresed the concentrations of PGE2 and PGF2α, and strengthened the contractibility of pregnant uterine.