Pandas have become important diplomatic symbols, not only to China. In a visit by Hu Jintao to Japan in May 2008, China announced the loan of two pandas to Japan. The President was quoted as saying "Giant pandas are very popular among the Japanese, and they are a symbol of the friendly ties between Japan and China." Actions that other countries take with pandas are often seen as laden with meaning. For example, British diplomats worried that a 1964 transfer of a panda from a London zoo to Moscow would worsen Sino-Soviet relations. In January 2006, U.S. Deputy Secretary of State Robert Zoellick was photographed hugging a 5-month-old panda cub during his visit to Sichuan Province. The image was widely broadcast by the Chinese media and was purportedly interpreted as a sign that Zoellick supported better relations between China and the United States.

Answer this question: what is the panda a symbol of in china? Let's think fast. Stream of consciousness:
The important part for answering this question is: Pandas have become important diplomatic symbols, not only to China. So the final answer is diplomatic symbols.