A Chinese woman from Guangdong Province found offensive language scribbled on page 8 and 24 of her passport as she went through immigration at the Tan Son Nhat International Airport in Ho Chi Minh City.
She was on a personal travel to Vietnam and did not react immediately when she saw the remarks on her passport. She later told China National Radio that she was "very disappointed at the personal qualities of Vietnamese officials."
The Chinese consulate general said that the act of the Vietnamese immigration officials was "shameless and cowardly."
In a statement released on Wednesday, the consulate general expressed through their website that they feel "indignation, contempt and condemnation to the Foreign Affairs Office in Ho Chi Minh City."
The Chinese government officials asked that the people responsible be reprimanded.
The Vietnamese government told the Chinese consul that they will investigate the matter.
Both the consulate in Ho Chi Minh and the embassy in China refused to comment.
The offensive action from the Vietnamese was connected to the dispute over the South China Sea. Both countries are claiming parts of the controversial waters.
Since 2012, Vietnam has refused to stamp Chinese passports that showed the dotted lines on the South China Sea. Chinese travelers have been issued separate visas.
The dotted line on the Chinese passports' design is the nine-dash line, or a representation of China's territory on the South China Sea.
Other countries that are disputing China's claim are Taiwan, Malaysia and the Philippines.
Li Guoqiang, deputy head of the Chinese Academy of Social Sciences' Institute of Chinese Borderland Studies, said that Vietnam has a "long-standing irrational emotional reaction" to the South China Sea issue.
He said, "However, this will not help to properly settle disputes between Beijing and Hanoi, and even hurts relations between the peoples of both countries."