A assembling frame for back light modules for securely assembling and anchoring the elements of a back light module and providing a selected deformation to overcome the impact on the back light module resulting from usage and environmental conditions, and including a flexible latch blade on a assembling frame to hold a lateral side of the light guide panel and accommodate the deformation occurring to the light guide panel after having absorbed water and expanding or warping. The anchoring relationship may be maintained even when the light guide panel is in usage or various environmental conditions such as high temperature and high humidity.