Prof. K. Sch?fer and P. Suppen from the Forschungszentrum Karlsruhe and Prof. J. Vogt and S. Norra from the University of Karlsruhe arrivalled at the Institute of Atmospheric Physics on Feb 23, 2009 to make an co-operational experiment and academic exchange with the Sub-Center of Atmospheric Science (SCAS) for one week, in order to accelerate the joint research projects on atmospheric issues of Megacities. They have done some operational experiments using the weather zeppelin and lidar at Xianghe station; in addition, the passive multi-level aerosol composition sampler has been tested in the 325m meteorological tower in IAP. On Feb 26, the academic exchange conference leading by Prof. P. Suppen and Yuesi Wang held, and more than 30 persons joined. The exports both form China and Germany introduced their institutes, research fields and results, respectively; meantime, aiming at the air pollution condition in Beiing and its surrounding areas, they do broad and deep exchange and discussion. In the end, the longtime cooperation plan has been made. (Provide by SCAS/LAPC)