Both countries and Taiwan claim Scarborough Shoal, known as Huangyan Island in China and Panatog Reef in the Philippines. The triangular atoll of reefs and rocks is in the middle of important fishing grounds.
China's state-run Xinhua news agency said hundreds of Chinese have been forced to change their travel plans due to safety concerns.
The Chinese embassy in the Philippines warned this week of massive anti-China demonstrations planned in the Philippines. Chinese citizens who are in the Philippines were urged to be cautious.
China says the Philippines risks further damaging diplomatic relations by provoking demonstrations with its remarks about Huangyan Island.
"We hope the Philippines will not further damage bilateral relations," Foreign Ministry spokesman Hong Lei said.
Xinhua said Chinese visitors are an important segment of the Philippines tourism industry.