Abstract: The nucleate boiling heat transfer characteristics of a bar water jet impingement on a large flat superhydrophilic surface were experimentally investigated.The superhydrophilic heat transfer surface was formed by a TiO₂ coating process.The experimental results were compared with those from the common metal surface.In especial,the quantificational effects of the flow conditions,heating conditions and the coating methods on the critical heat flux（CHF） were systemically investigated.The experimental data showed that the nucleate boiling heat transfer from the superhydrophilic surface was significantly different from those from the common metal surface.The critical heat flux of boiling on the superhydrophilic surface was greatly increased by the decreasing of the solid-liquid contact angle.