We study cleaved surface of a single crystal of p-nitroaniline by laser microprobe technique with SHG detection. The surface is scanned with a tightly focused beam from a Q-switched Nd:YAG laser, while SHG is monitored. There is a strong variation of the SH intensity, although angular as well as polarization dependence indicates well-ordered alignment of molecules on the surface. Possible origin of this inhomogeneity is discussed.