Abstract: A built tinpiate working line of a cold rolling mill in Wuhan Iron and Steel Work, Hubei, PRC, was extended. It was required that the air exhauster chamber should be demolished.Air exhauster chamber was located in the northeast end of the fifth rack of the mill, 9m away southwest there was the electric control chamber, 29m away was the electric computer room, and 30m away northward was a switch station. In the northeast elevated about 5m high was the mixed gas pipelines of coal, hydrogen and nitrogen. On the roof and by the sides there were pipes for compresed air and water. Close to four corners of the air exhauster chainber which was planned to be demolished, there were four building columns only 380mm apart, and the column foundations were very close to the ventilation galleries.All these structures, instrumentations especially the electric computer mentioned above are very sensitive to vibration Induced by blasting. The safety of the coal gas pipsline should be absolutely guaranteed and not to be damaged by blaeting. Therefore such a blasting project is a highly difficult one, its key point is the effect of blasting on the environment. It is required that the work must be absolutely safe and reliable, and the normal operation of the mill should not be disturbed.