Abstract:AIM:To study the effect of Urotensin Ⅱ(U-Ⅱ) on intraocular pressure(IOP).METHODS:Different concentrations of U-Ⅱ(10pg/μL,100pg/μL,1ng/μL,10ng/μL) were injected into anterior vitreous body of eyes in New Zealand rabbits.Schiotz impression tonometer were used with double balances after 0,1 hour;2,4,6,8,10,12,24,36 hours;2,3,4,5,6 days.RESULTS:IOP decreased 17.5%,33.7%,54.7% and 56.4%(P<0.001) in groups of 0.1ng U-Ⅱ,1ng U-Ⅱ,10ng U-Ⅱ and 100ng U-Ⅱ after 10-12 hours,8 hours,6 hours and 6 hours respectively;The effects of IOP decreases continued until 24 hours;2,3,4 days respectively.CONCLUSION:U-Ⅱ can decrease intraocular pressure(IOP) rapidly,intensively and continuously.U-Ⅱ,the new biological activity substance may become an effective medicine to prevent and treat glaucoma.