Abstract: A short length room temperature sealed off CW CO laser has been described.It has an active medium length of 80cm,uses a gas mixture of He:N2:CO equals 73:35:1,cooled with running water at 10℃,laser transitions have been observed in ten rovibrational band,covering the spectral range from 5.0 to 6.0cm.The output is 0.2W.Especially with only half discharge,that means an active medium length of 40cm it could still give out 30mW laser output.