Abstract: Along with China's economic development and the improvement of investment environment,TNCS rapidly entered the Chinese market by means of M A,enjoyed higher market share with capital,technology and brand advantages.Meanwhile,the growing M A cases have brought disputes on whether M A will form monopoly and how to regulate monopoly behaviors.The anti-monopoly regulations on M A in the Occident are analyzed in terms of legislation and practice,especially the definition of the relevant market and the criteria of monopoly.Then it analyzes some countermeasures for China based on some M A cases in China and our anti-monopoly laws and regulations.