In terms of the common green buildings techniques obtained from statistics and climate features of hot-summer and cold-winter zone in China, a case study has been done. The effects of techniques, such as the enhancement of the performance of building envelope, energy comprehensive utilization, have been analyzed. The results show that the energy-saving benefit from total heat recovery of exhaust air which reaches 35% is the biggest in those common green buildings techniques; the utilization of fresh air in interim can save 10% energy; it could save as much as 7% energy by the means of setting adjustable exterior shading or improving the thermal performance of building envelop; the energy-saving rate of light control is 12.3%, etc. The study indicates that the energy efficiency of green buildings techniques interact with each other. Therefore, a comprehensive consideration of an energy conservation scheme of green buildings must be taken. The results show comparing with the requirements of current energy-saving standards, the whole energy efficiency of green buildings can achieve 46.9%, which can save energy by 75% compared with the reference building in the current energy-saving standards.