To evaluate the curative effects and complications of conventional, microscopic and endoscopic intranasal ethmoidectomuies, 130 cases of sinusitis and polys (stage II) were operated on with intranasal ethmoidectomies. There were 40 conventional, 40 microscopic, and 50 endoscopic ethmoidectomies, followed-up with endoscopy and CT scanning. The results showed that 1. the relieve of symptoms in the endoscopic group(94.0%) was obviously better than the conventional (60.0%) and the microscopic groups (70.0%, P < 0.01): 2. the clinical cure rate in the endoscopic group (86.0%) was obviously higher than the conventional (40.0%) and the microscopic groups (52.5%, P < 0.01); the CT scans showed a normal ratio in the endoscopic group(82.0%) obviously higher than those in the conventional (22.5%) and microscopic groups (37.5%, P < 0.01); 3. the complication ratio in the endoscopic group(12.0%) was slightly higher than those in the conventional(5.0%) and the microscopic groups (2.5%, P > 0.05). The intranasal endoscopic ethmoidectomy was more successful than the conventional and microscopic ethmoidectomies, but attention should be paid to the possibility of complications.