The main cases represented by Guo Shan are: the construction project dispute between Beijing International Trade City Real Estate Company and Beijing Ju 'an Jinrun Real Estate Company; the national debt investment and loan dispute between Ganzhou City Commercial Bank of Jiangxi Province and Bank of China Beijing Branch; the guarantee dispute between Zhengzhou City Commercial Bank of Henan Province and Henan Securities Company; the patent infringement case of "Bei Jia"; the patent invalidation request case of "Bei Jia"; the trademark infringement case of "Generation Tianjiao"; and the trademark administrative litigation case of "Wedding Banquet". Trademark infringement case of "Lao Cao Fang", contract dispute between Qizhi Software (Beijing) Co., Ltd. and Baidu Times Network Technology (Beijing) Co., Ltd., lease contract dispute between Beijing Longteng Jinxiang Catering Co., Ltd. and Beijing Yindu Real Estate Development Co., Ltd., trademark infringement dispute between Jiangsu Dawei Technology Co., Ltd. and Hanwang Technology Co., Ltd., invention patent and utility model patent infringement dispute case; German HUCHTEMEIER HEINZEL PAPIER Co., Ltd. v. China Metallurgical Import & Export Hebei Company (case of purchase and sale contract dispute); Nanjing Shi Jia Medical Consulting Co., Ltd. v. Bosport Lomb Company; And the international arbitration case of the cooperation dispute between Guangzhou Tunnel Development Company and Virgin Guo Fu Development Co., Ltd. in Hong Kong.