Abstract: A new technology of production logging with looped pipeline was introduced to suit to sallow horizontal well with viscous oil. Using special downhole testing instrument set and wellhead sealing installation, the testing instrument can be sent to the predict horizontal site in the looped pipeline by pumping instruments. After heat exchanging for a certain time and getting equilibrium, the temperature can be tested spot by spot in the horizontal well by the logging wire or cable. By the field testing, it is verified that the technology has simple structure, easily implement, safe and not stop pump to test. The technology suit to the horizontal well’s production logging.