The symplectic mapping class group of CC P² n{bar{CC P²}} with nleq4

In this paper we prove that the Torelli part of the symplectomorphism groups of the $n$-point ($n\leq 4$) blow-ups of the projective plane is trivial. Consequently, we determine the symplectic mapping class group. It is generated by reflections on $K_{\omega}- $spherical class with zero $\omega$ area.