The utility model relates to a guardrail is used to bed, horizontal pole and montant including interconnect, the horizontal pole with the montant is articulated each other, the horizontal pole is in between two montants, the lower extreme of two montants is direct articulated with the bed frame, two montants with the articulated department of bed frame has locking means, install on arbitrary montant can carry on the level folding or along with folding U -shaped guardrail about the montant goes on, the U -shaped guardrail can along with the motion of montant converts vertical position into by horizontal position. It is more reasonable that this guardrail is used to bed compares with the design of current guardrail, and the horizontal pole swells at rotating folding back nothing between the montant, is less than the mattress, and full encirclement protection can be realized to the U -shaped guardrail of increase.