Abstract: A telescopic glareshade is provided with an outer shelter and an inner shade board which is adjustably engaged with the outer shelter. The inner shade board has a bulged top end having a mushroom shaped cross section which can be in frictional contact with the inner faces of the outer shelter so as to constantly retain the shade board in place. The outer shelter has a longitudinal extended opening for the passage of the inner shade board and a pair of parallel stop flanges are defined on the edges of opening so as to prevent the inner shade board from disengagement from the outer shelter when pulled down to the bottomost end.