Visa is required for citizens of China to visit Vietnam. Chinese nationals may have 2 options: Visit Vietnam embassy in China (Beijing) or apply for a visa on arrival to Vietnam from China online. Chinese citizens may apply for both tourist and business visa to Vietnam for the stay of 1 to 6 months from China. Please check this link for visa fee for Chinese citizens.
All the information for getting a visa from Vietnam embassy in China can be found here: www.vnemba.org.cn/
Related reading
Vietnam embassy in Beijing
Vietnam Consulate in Shanghai
Vietnam consulate in Guangzhou
Vietnam consulate in Kunming


