Generally, you may reach China International Exhibition Center by taxi no matter where you get off. But, you also could choose other ways.

From Airport:
20 kilometers to China International Exhibition Center, it takes 30 mimutes by shuttle bus, or take subway to Dongzhimen Station and get off at Sanyuanqiao Station, walk 10 minutes northward.

From Beijing West Railway Station:
Take No. 387 bus to Beitaipingzhuang Station and switch to No. 300, 830, 730 or 731 and get off at Jinganzhuang Station. Or take subway to Sanyuanqiao Station, walk 10 minutes northward.

From Beijing Raiway Station:
Take subway Line 2 to Dongzhimen Station and then go to the Center by taxi.