As our country accepted most institutions and theories of the continental jurisprudence, when we talkabout the concept of ‘a law’, that word also presupposes ‘legal system’. In the thinking of judicial methodology, a “legal system” is not only the sum-total of law or legal material; it represents the pattern of interrelation of this material and differs from them alsoin its overall purposes and functioning. Thus, the quantity of the laws and regulations in a modem country is out of number. Sometimes we find that one fact according to different laws and regulations but with different legal results . That means there will be contradictions in the legal system. To solve this problem and keep the unity or coherence of the legal system, the courts have to decide which one precedes the others among the conflicting laws or regulations. There are three old rules in jurisprudence: “lex superior derogat legi inferiori”, “lex posterior derogat legi priori” and “lex specialis derogat legi generali”. For other considerations, there are also new rules expressed in other laws, for example, in criminallaws. When the result of which law or regulation has precedecy is easier recognized by the people, not only the lawyers, there is more predictability of laws.