Spatially resolved measurements of OH*, CH*,and C2* chemiluminescence in laminar premixed methane-air flames operated at several equivalence ratios ranging from 0.85 to 1.5 are performed to reveal the reaction zone structures. The measurement system consists of Cassegrain optics,an optical fiber, and a monochromator coupled with liquid nitrogen cooled charge-coupled device (LN-CCD). Experimental results indicate that this non-laser based chemiluminescence optical probe can accurately measure the radial distributions of OH*, CH*, and C2* in slot burner flames. The ability of using the intensity ratio of C2*/OH*,C2*/CH*, CH*/OH*, and C2*(1,0)/C2*(0,0)obtained in laminar flames for simultaneous measurements of local equivalence ratio and temperature in turbulent flames is discussed.