Abstract: The major reason for the failure to effectively curb economic crimes is the difficulties in discovering and obtaining of evidence in good time.And this makes it increasingly difficult to fight against economic crimes.The difficulties are mainly due to the retard of the disclosing of crimes and the unique nature of evidence.The inadequate economic police force，involvement of government officials in such crimes，unwilling and hesitated cooperation of the general public in evidence collecting are other reasons for such difficulties.Therefore，the authors conclude that overcoming of the difficulties lies in the promotion of professional qualification of economic police force，a command of the unique features of economic crimes and a closer cooperation with financial organizations.

Key words: economic crimes, crime investigation, evidence, documentary evidence, investigation method 