Abstract: Baiyun （BY） 6-1-1 well is in the east of South China Sea and its water depth is 1036m. It the second well in China,with the water depth more than one thousand meters. The well structure and casing program, the bottomhole assembly （BHA）, majoroperating procedures and techniques are used to the deep drilling operation of BY6-1-1 well, solving the problems caused by deep waterdrilling and improving drilling efficiency. The success will exert great effect on deep water drilling in China in the future, and also maybe a good reference to the development of drilling techniques in the country.