The deep understanding of transient pool boiling critical heat flux (CHF) phenomena with treated surface and its correlation in water at saturated and subcooled condition are becoming increasingly important for the database of the further enhancement of the design of liquid cooling technologies in a nuclear reactor. The pool boiling CHF has been reported assuming on non-hydrodynamic instability on the effects of surface and contact angle using horizontal vertically oriented ribbons heaters in some liquids. In the present research, the steady and transient CHF have been performed due to exponentially increasing heat inputs mainly from 5 ms to 10 s on a horizontal vertically-oriented platinum ribbon in a pool of water for a range of pressure and subcooling. The three ribbon heaters with different surfaces, namely, commercial surface (CS), treated surface I (TS-I) and treated surface II (TS-II) are used. TS-I and TS-II are prepared from commercially available ribbon by finished with buff paper and emery paper, respectively. For the surface condition, surface roughness and contact were measured prior to pool boiling experiment. The non-boiling heat transfer processes are corresponding to the natural convection and the transient conduction equation, respectively. The steady-state CHFs for subcoolings and pressures, respectively, measured on TS-I are lower than corresponding values attained from commercial surface. The transient CHF, q_<cr> , on shorter period are higher than longer ones. The transient CHF, q_<cr>, of TS-II for periods in this study is higher than that of TS-I at long period. The first group of CHF on TS-II is longer than CS and TS-I, on the contrary, the second group of CHF was not observed on TS-II at atmospheric pressure under saturated condition. The increasing trend of transient CHF under saturated condition depends on pressure. The increasing trend of transient CHF under subcooling of 20 K will be become independent at pressure higher than 199 kPa. Finally, steady-state CHF were established with well-known data, respectively.