The relationships between structural features of minoxidil analogues and their inhibitory activity against LH (lysyl hydroxylase; EC.1.14.1.14) in human skin cultured fibroblasts were discussed. In order to present the basic data for searching new better materials from this result, CoMFA was performed and the result was analyzed quantitatively. From the information of the optimized CoMFA model (q2 = 0.480 & r2nev = 0.965), the inhibitory activities were found to depend upon the steric field (37.4%) and electrostatic field (58.7%) of the molecule. Therefore, it was concluded that the electrostatic field was the main increasing factor in the inhibitory activity. According to the graphical analyses of the contour maps with the optimized model, we found that the inhibitory activities of piperidinyl group were dependent on the steric field and hydrophobic field and those of pyrimidine-1-N-oxide group were dependent on the electrostatic field.