In this article, a loop that is partly electrostatic shielded is analyzed. It is found that the line integral of electrostatic field around this loop is not zero. This is against the theorem that the line integral of electrostatic field around any closed loop is zero and the curl of electrostatic field is zero. When the loop is made of conductor wire, there is no electric current flowing around the loop although the line integral of electric field is not zero. A loop current driven by electrostatic field will break the law of energy conservation, so it is expected and reasonable that we cannot observe a current in the loop.