Abstract: In this paper,we introduce a polynomial sequence in K[x],in which two neigh- bor polynomials satisfy a wonderful property.Using that,we give partial answer of an open problem: if φ(x,y,z)=(f(x,y),g(x,y,z),z),which sends every linear coordinate to a coor-dinate,thenφis an automorphism of K[x,y,z].As a byproduct,we give an easy proof of the welt-known Jung’s Theorem.

Key words: coordinate polynomials, Jacobian Conjecture, polynomial automorphism, tame
automorphism, algebraically closed field