Noncontact atomic force microscopy (AFM) provides useful technique for imaging organic molecules in high resolution. Here we present our recent advances in the noncontact AFM imaging of organic materials. (I) Molecular packing structures, defects and domain boundaries were clearly observed on adenine and thymine films. The noncontact AFM images revealed detailed features of the individual nucleic acid base molecules, thus allowing us to distinguish between adenine and thymine. (II) Both (root 3 X root 3)R30 degrees structures and c(4 X 2) superlattice structures were resolved on alkanethiolate self-assembled monolayer (SAM) [CH3(CH2)(8)SH] (nonanethiol) on Au(111). We found that the c(4 X 2) superlattice structures changed into (root 3 X root 3)R30 degrees structures when the tip-surface distance decreased.