Based on an existent passive office building in cold areas, two different models were set up according to actual condition and domestic design standard by using the eQUEST software. Ten cities located in different provinces in North China were selected to compare the energy consumption of air conditioning. The results show that the passivhaus have almost the same energy consumption in summer with the normal buildings, but in winter, the heating energy consumption of the passivhaus has great decline. On the comprehensive energy consumption of air conditioning, Taiyuan has the largest energy saving potential. In Taiyuan and Harbin, the passivhaus's air conditioning energy consumption is 54.16% and 34.06% less than the domestic normal buildings respectively. Passive office building has great potential for energy saving in northern China.