To investigate effects of l% l-acetylforskoin (l-aF) suspension eye-drops administeredtopically on intraocular pressure (IOP) in rabbits and men, and observe the loca l irritation of the drug． l% l-aF suspension eye-drops was prepared and was instilled into one of e yes while the corresponding vehicle into the contralateral eye as control． IOP was measured b y pneumatonometer before and after administration． l%1-aF suspension eye-drops s ig nificantly reduced IOP in rabbits reaching the maximum reduction of 2.2 mmHg and lasting a t least 3 hours． But it didnt show significant effects in men． There was little local irritati on neither in rabbits nor in men． l% l-aF suspension eye-drops significantly reduced IOP in normal rabbit s, but not in men． No local irritation was observed in rabbits and in men．