In an assembling structure for LED road lamp and heat dissipating module, the LED road lamp includes a partition board, an upper casing, a light transmitting lens and an LED lamp set. The upper casing and the light transmitting lens are set separately on upper and lower sides of the partition board. Each LED lamp set is contained in a space enclosed by the partition board and the light transmitting lens. The partition board has a plurality of through holes, and the LED lamp set includes a frame body and an LED module. The heat dissipating module includes a heat dissipating body, a heat pipe and an isothermal board. The heat dissipating body is set in a space enclosed by the partition board and the upper casing, and the heat pipe has a heat discharging end passing through and connecting the partition board and the heat dissipating body and a heat receiving end forming the bottom of the partition board. The isothermal board is fixed onto a frame body of the LED lamp and has two planes separately attached onto the heat receiving end and the LED module, so as to significantly enhance the overall heat conducting and dissipating performance, drive an LED to emit light at a lower temperature, and extend the life expectancy of the LED.