Detention and summoning, refers to the investigative organs of criminal suspects who are not in custody to force them to come to the case to accept the interrogation of a criminal coercive measures. The public security organs, the people's procuratorate and the people's court of the criminal suspects and defendants who have not been detained, according to law to force them to come to the case to accept the interrogation of a compulsory measure. Custodial summoning is the system of coercive measures in China's criminal procedure is the least coercive, the public security organs, the people's procuratorate and the people's court in the process of criminal proceedings, have the right to decide to apply.