Two C-60 derivatives, dodecylaminofullerene (DAF) and multihydroxydodecylaminofullerene (MHDAF) were prepared. The isotherms showed that the limiting molecular areas of DAF and MHDAF are around 60 Angstrom(2) and 64.7 Angstrom(2) respectively, which suggests that the aggregations of the molecules at the air-water interface are decreased compared with that of C-60. The best transfer ratio could be enhanced to 0.7-1 by using the vertical dipping method. The structural characteristics of DAF Langmuir-Blodgett (LB ) films were studied by W-Vis spectroscopy, atomic force microscopy and transmission electron microscopy. The second-order susceptibility chi((2)) and molecular hyperpolarizability (beta) of 12-layer LB films of DAF are determined to be 3.26 x 10(-6) esu and 1.46 x 10(-28) esu respectively.