Abstract: The ordinary treatment of circulation loss during drilling operation is to stop water loss firstly and then to drill,but problems such as long loss time and large consumption of chemicals and lost circulation material.After analyses on the circulation losses in different strata at Khurais area,Saudi Arabia,techniques and matching measures of continuously drilling while circulation loss,sweeping by high viscous mud,diesel—emulsified mud and double-stage cementing are concluded.The successful practices of the techniques and measures accelerate the drilling operation,and reduce the drilling cost.