Abstract: Comprehensive researches of the downhole thermocouple temperature log data reveal the thermal interconnecting characteristics between wells and the distribution of steam on profile. It is found that the time of observation wells being interfered is two times of producing wells, the low limit of the steam breakthrough temperature is about 60 ℃ , and that only one third of the vertical thickness of reserviors is heated, steam sweep thickness is 13.2%, and the steam is seriously overlaid. The key factors to improve the development efficiency include steam channeling prevention and channeling plugging techniques in time and optimizing perforating thickness, enlarging the sweep volume, and developing the low temperature section of bottoiruof reserviors.