Abstract:
                                      Let 
\Re 
 be a unital prime *-algebra of characteristic 2 containing a nontrivial symmetric idempotent. For 
A,B \in \Re
, the new product and 2-new product are defined, respectively, by 
A \cdot B\rm = AB + BA^*
 and 
(A \cdot B)_2 =   (A \cdot (A \cdot B))
. Let 
\phi :\Re  \to \Re 
 be a surjective map. It is shown that 
\phi 
 satisfies 
(\phi (A) \cdot \phi (B))_2\rm = (A \cdot B)_2
 for all 
A,B \in \Re 
 if and only if there exists 
\alpha  \in C_S
 with 
\alpha ^3 = I
 such that 
\phi (A) = \alpha A
 for all 
A \in \Re 
, where 
C_S
 is the symmetric extend centroid of 
\Re 
. As an application, such maps on prime 
C^*
 algebras and factor von Neumann algebras are characterized.