The purposes of this study are to investigate and analyze the actual conditions of the urban residential energy consumption, and hence to ascertain what will be the important factors that influence the annual energy consumption in Kunming, which has a mild climate. The questionnaire surveys reveal building characteristics, housing appliances, household characteristics, indoor thermal environment and aspects of life style, during winter and summer seasons. The questionnaire analyses show that only 5% of the investigated households have air conditioning, and 12% have heating appliances. Most households use solar energy as a water heater energy source because the sunshine hours in Kunming are long. The energy consumption analyses show that the average annual energy consumption of households in Kunming reached 12.2 GJ, and cooking accounted for 5.3 GJ, which is the largest part. Most of the time in summer, the outdoor temperature is lower than living room and bedroom temperatures; thus, natural ventilation is a useful cooling method for households in Kunming. The absolute humidity in summer is about 11 g/kg, while in winter it is about 5 g/kg. The influence factor analyses show that building construction year, water heater type and annual income are important influential factors on annual energy consumption.