The present invention provides a backlight module for a light emitting device (LED) chip holder. The backlight module includes a top guide-light board, a bottom guide-light board, a chip holder with an inclined plane thereon, and a light emitting diode chip. One side of the top guide-light board and the bottom guide-light board has a reflective sheet, and the light emitting diode chip is located on the inclined surface of the chip holder, and further the light emitting diode chip is embedded in the bottom guide-light. When the light emitting diode chip emits incident light, the light produces the total reflection on the bottom guide-light board to reflect to the reflective mirror. Then, the light is reflected to the top guide-light board by the reflective sheet, and is emitted out from the top guide-light board to be a light source for the backlight module.