The present invention discloses a heatsink apparatus for use with a backlight module. The heatsink apparatus is used to dissipate heat buildup from a light source, and includes a heatsink and a backframe. The heatsink is thermally in contact with the light source. The backframe and the heatsink jointly define a ventilation shaft on a surface of the backframe. The present invention further includes a backlight module incorporated with the heatsink. With the provision of the ventilation shaft of the heatsink, the performance of the heat dissipation is increased, and the service life of the light source is therefore prolonged.