An adjustable jig for retaining glass plate includes a frame, at least two clamp guides, and a plurality of clamp. The frame has a plurality of symmetric retaining component on two parallel frame columns. The clamp guide has a connecting portion for being retained by the retaining component on two ends of the clamp guide so that the clamp guide can be fixed across the parallel frame columns. The clamp guide has an approximated T-shaped guide on at least one longitudinal side of the clamp guide. The clamp has an approximated T-shaped groove and an approximated V-shaped groove. The T-shaped groove serves to be slid into the T-shaped guide so that the clamp is sliding along the clamp guide for clamping glass of any size or shape The glass will be firmly clamped by multiple clamps through predetermined positions without risk of breakage.