A window roller shade box, having a three-part structure with three profile elements that are detachably connected to one another,wherein the window roller shade box comprises a top strip a back strip and selectively a front strip (16, 20) or an adapting element, wherein the profile of the top strip is a long arm provided at its each end with a bend and an irregularly shaped supporting wall, wherein each bend having the same bend radius and being directed towards the inside, said arm is also provided with catch elements (8, 9) positioned opposite and symmetrically and a projection positioned centrally between the catch elements (8, 9); wherein each bend and the corresponding supporting wall form a seat for detachably connecting: the back strip, the front strip (16, 20) or the adapting element; wherein the profile of the back strip is a long arm, said arm inclined at angle α by the first groove and provided with a second groove having the same diameter d, with the second groove having an edge shared with a T-shaped groove, the latter being the tip of the arm at one of the ends of the arm, with the other end of the arm having a curvature that is directed towards the outside and is dedicated to be detachably connected with the seat of the top strip that is formed between the bend and its corresponding supporting wall at the one end of the top strip; wherein the profile of the front strip (16, 20) is a long arm, whose bottom end is provided with a groove with an edge shared with a T-shaped groove, the latter being the tip of the arm of the front strip (16, 20), with the top end having a curvature (19, 22) that is directed towards the outside and is dedicated to be detachably connected with the seat of the top strip that is formed between the bend and its corresponding supporting wall at the second end of the top strip; wherein the adapting element has a cross sectionally U-shaped groove and is provided with a curvature that is directed towards the outside and is dedicated to be detachably connected with the seat of the top strip that is formed between the bend and its corresponding supporting wall at the second end of the top strip. wherein the profile of the top strip is a long arm provided at its each end with a bend and an irregularly shaped supporting wall, wherein each bend having the same bend radius and being directed towards the inside, said arm is also provided with catch elements (8, 9) positioned opposite and symmetrically and a projection positioned centrally between the catch elements (8, 9); wherein each bend and the corresponding supporting wall form a seat for detachably connecting: the back strip, the front strip (16, 20) or the adapting element; wherein the profile of the back strip is a long arm, said arm inclined at angle α by the first groove and provided with a second groove having the same diameter d, with the second groove having an edge shared with a T-shaped groove, the latter being the tip of the arm at one of the ends of the arm, with the other end of the arm having a curvature that is directed towards the outside and is dedicated to be detachably connected with the seat of the top strip that is formed between the bend and its corresponding supporting wall at the one end of the top strip; wherein the profile of the front strip (16, 20) is a long arm, whose bottom end is provided with a groove with an edge shared with a T-shaped groove, the latter being the tip of the arm of the front strip (16, 20), with the top end having a curvature (19, 22) that is directed towards the outside and is dedicated to be detachably connected with the seat of the top strip that is formed between the bend and its corresponding supporting wall at the second end of the top strip; wherein the adapting element has a cross sectionally U-shaped groove and is provided with a curvature that is directed towards the outside and is dedicated to be detachably connected with the seat of the top strip that is formed between the bend and its corresponding supporting wall at the second end of the top strip. the back strip, the front strip (16, 20) or the adapting element; wherein the profile of the back strip is a long arm, said arm inclined at angle α by the first groove and provided with a second groove having the same diameter d, with the second groove having an edge shared with a T-shaped groove, the latter being the tip of the arm at one of the ends of the arm, with the other end of the arm having a curvature that is directed towards the outside and is dedicated to be detachably connected with the seat of the top strip that is formed between the bend and its corresponding supporting wall at the one end of the top strip; wherein the profile of the front strip (16, 20) is a long arm, whose bottom end is provided with a groove with an edge shared with a T-shaped groove, the latter being the tip of the arm of the front strip (16, 20), with the top end having a curvature (19, 22) that is directed towards the outside and is dedicated to be detachably connected with the seat of the top strip that is formed between the bend and its corresponding supporting wall at the second end of the top strip; wherein the adapting element has a cross sectionally U-shaped groove and is provided with a curvature that is directed towards the outside and is dedicated to be detachably connected with the seat of the top strip that is formed between the bend and its corresponding supporting wall at the second end of the top strip.