An improved round corner cutting machine that is configured for accommodating and separating sharp cornered bound instruction books of different size that are linearly adjacent to each other at partition line and for round corner cutting of accommodated and separated sharp cornered books characterised in that it comprises: a book separator sucker assembly for accommodating and separating the adjacent sharp cornered books from their partition line, a book gripping assembly configured for griping the book along a lateral edge and conveying the books towards the book separator assembly and a back stopper assembly, the back stopper assembly for adjusting the position of the separated sharp cornered book and a corner cutting assembly for performing corner cutting operation onto the sharp cornered books positioned by the book stopper assembly; wherein said book separator sucker assembly comprises linearly arranged sucker mounting linear guide blocks (100, 101, 102, 103), a cam operated lever being connected to a cam shaft through an eccentric bracket, connecting links (107, 108), pairs of sucker cups for gripping books, a middle sucker cup positioned on centre line such that it divides equal numbers of pairs of sucker cups at its both sides and holds middle book in case of odd numbers of books to be separated, one end of each said connecting link (107, 108) is connected to the lever and another end of each link (107, 108) is respectively connected to the guide blocks (100, 101) through bolts; wherein each said guide block (100, 101, 102, 103) is configured with two extended adjustment slots, each said guide block (100, 101, 102, 103) is connected with the pair of sucker cups by securing the sucker cup through the adjustment slot by fastening means; wherein each sucker cup is equipped with a sucker for griping the books; wherein the distance between suckers of each pair is adjusted by loosing the securing means and sliding the sucker cups within the adjustment slots; wherein each pair of sucker grips at least one book; wherein said guide blocks and are equidistantly moved in opposite direction with respect to centre line; wherein said guide blocks and are equidistantly moved in opposite direction with respect to center line; wherein each pair of sucker travels along with the movement of corresponding guide blocks (100, 101, 102, 103) through the cam operated lever so that the books are separated from their partition line along with the separation of the pairs of suckers. a book separator sucker assembly for accommodating and separating the adjacent sharp cornered books from their partition line, a book gripping assembly configured for griping the book along a lateral edge and conveying the books towards the book separator assembly and a back stopper assembly, the back stopper assembly for adjusting the position of the separated sharp cornered book and a corner cutting assembly for performing corner cutting operation onto the sharp cornered books positioned by the book stopper assembly; wherein said book separator sucker assembly comprises linearly arranged sucker mounting linear guide blocks (100, 101, 102, 103), a cam operated lever being connected to a cam shaft through an eccentric bracket, connecting links (107, 108), pairs of sucker cups for gripping books, a middle sucker cup positioned on centre line such that it divides equal numbers of pairs of sucker cups at its both sides and holds middle book in case of odd numbers of books to be separated, one end of each said connecting link (107, 108) is connected to the lever and another end of each link (107, 108) is respectively connected to the guide blocks (100, 101) through bolts; wherein each said guide block (100, 101, 102, 103) is configured with two extended adjustment slots, each said guide block (100, 101, 102, 103) is connected with the pair of sucker cups by securing the sucker cup through the adjustment slot by fastening means; wherein each sucker cup is equipped with a sucker for griping the books; wherein the distance between suckers of each pair is adjusted by loosing the securing means and sliding the sucker cups within the adjustment slots; wherein each pair of sucker grips at least one book; wherein said guide blocks and are equidistantly moved in opposite direction with respect to centre line; wherein said guide blocks and are equidistantly moved in opposite direction with respect to center line; wherein each pair of sucker travels along with the movement of corresponding guide blocks (100, 101, 102, 103) through the cam operated lever so that the books are separated from their partition line along with the separation of the pairs of suckers.