The size of the passively urbanized group is becoming huger with the rapid urbanization in China. The process of entering city means that they are obtaining urban adaptability and modernity. Based on the survey data of 561 land-displaced peasants in Nanjing in 2004, and from the view of self-identity, the paper shows that the land-displaced peasants are experiencing self-identity maladjustment. Most of them have not attained their self-identity in the new system, mainly because they are passively urbanized. The "time effect" causes their self-identity transition to lag behind their physical migration and the strong sense of relative deprivation in consequence of the "space effect" also impedes the transformation of their self-identity system. Based on the above analysis, the paper puts forward a proposition yet to be further examined-the social reference frame/system of self-identity of the passively urbanized group is taking on some special characteristics of practicalness.