In the framework of the ATMS method the charge form factors (CFF) of 3He and 4He are investigated using the wave functions obtained from various realistic two-body potentials. The two-body potentials used are the Hamada-Johnston, the Tamagaki (OPEH and OPEG) and the Obinata-Wada potentials. The calculated CFF's of 3He and 4He are in good agreement with the experiments at low momentum transfers and do not reproduce the characteristic diffraction structures completely at high momentum transfers. Difficulties in the usual reaction matrix method for CFF of 4He and the removal of the center of mass motion are discussed. By taking advantage of the ATMS method, the short-range and long-range correlations which reproduce the experimental CFF are searched for extensively. It is found that such correlations give less binding energies. Inclusion of the three-body force is considered, but results are hardly improved. It seems that CFF's at high momentum transfers are not fully understood within the nucleon degrees of freedom.