In this paper,we introduce the ${\tau _{\left[ n \right]}}$-mutations of a class of Koszul algebra,and show that the $n$-APR tilts of Koszul algebra $\Lambda $ is ${\tau _{\left[ n \right]}}$-mutation of $\Lambda $ if the global dimension gl. dim $\Lambda \le n$ and the Koszul dual of $\Lambda $ is an admissable $\lef...