Spherical chen surfaces which are mass-symmetric and of 2-type

The main purpose is to classify spherical Chen surfaces which are mass-symmetric and of 2-type. We prove that these surfaces are either pseudoumbilical or flat,moreover,in the later case,they lie fully in a 3-sphere,a 5-sphere,or a 7-sphere. Our result divides the family of such surfaces into four classes. In the last section, we give examples of surfaces which belong to each of these four classes.