There are strong and complex interactions among bubbles and nucleation sites during nucleate boiling process. In the present paper, the thermal interaction among bubbles through the temperature field on a heating wire is discussed. When one bubble generates and grows at one site, it will cause temperature change of the heating wall. This kind of temperature change would be sharp if the heating wire has small size and small heat capacity. In the paper, the influence of bubble forming and growing is discussed on wire temperature and bubble formation at adjacent nucleate sites, specially at two close sites. The analysis indicates that the small size and heat capacity of wire ought to be the reasons why boiling on the wire needs higher superheat than on a plate. The numerical calculation result of influence of bubble growth on superheat is consistent with analytical result very well.