The infrared and electronic absorption spectra of semicarbazide hydrochloride and its complexes with anthracene, tetracyanoquinodimethane TCNQ, Na fluorescein and cupferron was recorded in the regions 200-4000 cm and 200 -400 nm. The new bands that appeared in the complex spectra were assigned. The effect of the complex formation on the frequency and intensity of the active vibrational bands was also studied. The internal energy changes of the complexes were calculated in a new line of calculation spectrophotometrically to give a clear insight about the stability of the investigated complexes. The electrical conductivity of the complexes was measured in the temperature range of 25 C to 130°C. The activation energy was calculated and discussed on the basis of the spectroscopic information.