PURPOSE: To provide an air bag for front seat passenger, which can improve the performance for constraining an occupant sitting on the front passenger seat at a low cost and which can be manufactured easily.

CONSTITUTION: In an air bag main body 7 to be expanded at the time of front collision, shape of an abutment area 11a, which abuts on a front window, is formed into the same shape with an area of the front window, on which the abutment area 11a abuts. Coefficient of friction of the abutment area 11a is set larger than that of the other area of the air bag main body 7. When the air bag main body 7 is expanded, the abutment area 11a abuts on the front window tightly along the curve of the front window, and simultaneously, shape of the air bag main body 7 becomes asymmetry in the right and left.