Present invention teaches to make a Roman shade window curtain where a sliding locking mechanism is provided at the bottom beam of the rolling spool at the back side of the Roman shade, where the engaging positions between the rolling spool bottom beam and the pair of auxiliary rods can be set according to user preference, by sliding the locking tubes towards the middle to move the engaging point up and down, and by sliding the licking tubes to the left and right extremities for engaging the bottom to the desired fold line on the Roman shade.