Guodong Sun worked in Shenzhen Customs from 1986 to 2001. He started his career as a lawyer in 2001, and is mainly focused on customs disputes, international trade disputes, and intellectual property disputes. In 2005, he established the well-known service websites "www.customslawyer.cn" and "www.qgtong.com". In June 2006, he established one of the first team of customs lawyers in China, and was the initial promoter of "China Customs Lawyer" in China. Over the years, Guodong Sun has provided IPR customs protection services to many multinational companies and domestic enterprises; provided border protection legal services to many well-known brands, as well as filed infringement lawsuits and solved IPR disputes for them. He has provided many multinational companies and domestic enterprises with legal services on tariff planning, tariff disputes, commodity classification disputes, customs tax investigation, administrative penalties disputes, import-export compliance, cross-border e-commerce, etc. Guodong Sun is highly adept in handling major and complex smuggling cases, as well as tax evasion reduction cases. He has led his team in handling many major smuggling cases, involving amounts ranging from RMB100 million to RMB1 billion, and his team has had a significant impact in China, and has been highly successful.