Abstract: The study analyzed 4 typical sport crimes, holding that the legal standard and emotion standard of necessity principle in criminal law could effectively determine the boundary of criminal law for sport.Intentional injury or not is the division between guilty and not-guilty in sport; and taking dope consciously or unconsciously can determine the self-injury or criminal injury.Thirdly, the legal trading, transporting or producing dope or not is the basis for the judgment of crime of illegal business operations; and the qualification of public employment or not is the criteria of taking bribes in "fake ball" or"black whistle".Lastly, gabling behavior of the originators is the basis for the judgment of illegal business operation crime, as well as the verdict presupposition of not-guilty for individual gambling.