Abstract: Since the loss of circulation of drilling fluids may result in severe hazards,proper measures should be taken promptly when circulation is lost.Accurately determining precisely where the drilling fluids are being lost is of great importance for timely implementation of a relevant remedy.At present,it is much easier to identify the formations responsible for the lost circulation when it occurs at bottomhole than at other positions in the hole.Under such circumstances,an innovative detector to identify the precise location of circulations losses has been developed.By using three key parameters,temperatures,pressure and flow rate,the detector can effectively determine specific position of lost circulation.The detector can be installed near the bit by using subs,and can be delivered with drilling tools.Field testing of the innovative detector has been conducted in Well Y-96-X-1 of the Shengli Oilfield.Testing results showed that the innovative detector can be used to determine the position of lost circulation.In addition to saving time in measurement,the detector may provide valuable references for preparation of emergency programs in drilling fluid circulation lost.More studies are required to further enhance real-time performances of the detector.