A copper parallel channels test piece has built into the test section containing twenty five, one mm by one mm, parallel channels the channels were fifty mm long; the Heat-transfer coefficients for single-phase are reported. Micro- channel was Square shape and the test section has a glass top plate to permit visual observations. The data are taken while the rig is working .The test section is received the heat by an electric heater is associated normally with a boundary condition for constant heat flux. Because the important variation in the single-phase - heat-transfer coefficient in the inlet zone, the interceding copper and aluminum material is shown to make the test section close isothermal wall boundary condition. The heat conduction influence is taken into computation in the data analysis finally; the effective heat flux and the single-phase heat transfer coefficient are reported in this paper experiments and predictions. Key words— Single phase Heat transfer cofficients , Parallel channels ,Heat flux,Mass flux.