The present invention provides a backlight module and a light-emitting source package structure thereof. The light-emitting source package structure comprises: a heat-dissipation base, at least one chip and a heat-dissipation fixing element. The heat-dissipation base has a connection hole. The heat-dissipation fixing element further has a connection post and a heat-dissipation fin with an abutting surface, and the connection post of the heat-dissipation fixing element passes through a through hole of a fixed plate to fix in the connection hole, so that for closely aligning the abutting surface of the heat-dissipation fin and can abut against the fixed plate. Thus, and the heat-dissipation base and the heat-dissipation fixing element are stably fixed on the both sides of the fixed plate to ensure the tightly abutting relationship with the fixed plate and enhance the assembly reliability. Meanwhile, the heat-dissipation fin can additionally increase the heat-dissipation efficiency of the heat-dissipation fixing element. Thus, the temperature of the chip can be surely lowered to prevent from lowing the working efficiency of the chip. Hence, it is advantageous for the chip to stably work, and the lifetime thereof can be increased.