The radio-loud active galactic nuclei having the radio emission arising from a core region rather than from lobes are often referred to as “blazars” and include Flat Spectrum Radio Quasars (FSRQ) and BL Lacertae (BL Lac) objects. We present results of long term observations of FSRQs as well as BL Lac type objects by SHALON Cherenkov telescopic system at energies > 800 GeV.