Abstract: Realname registration system is a kind of simplistic approach to ascertaining responsibility in information space The mechanism of realname registration system is to map subjects in information space into those in real space onetoone beforehand, then depending on the existing imputation system of real space, to resolve the imputation problem in information space However, the fascination of information space lies in the perceived freedom when hiding Therefore, to let subjects in information space take off their invisibility cloak, “vigilantly and prudently” exist after mapping, although it does resolve imputation problem in information space, it eradicates the pleasant sensation at the same time To build subjects’ mapping database from information space to real space is an effective method of ascertaining responsibility in information space It not only reduces imputation cost under reasonable limit, but also does not excessively hurt the perceived freedom Mapping database belongs to national secret Nobody has the right to use it without permission from authority

Key words: informationspace, informationresponsibility, imputation, realnameregistrationsystem