The bi-modality in the distribution of galaxies usually obtained from colour-colour or colour-mass diagrams has been studied to show the difference between the “blue cloud” and “red sequence” galaxies and define the green valley region (transitional region), galaxies in it are expected to give clues in the understanding of the morphological and evolutional transformation of galaxies from late-types to early-types. In this research, we study how different green valley selection criteria used in previous works affect the final results and conclusions. We analyse the distribution of stellar mass, SFR and sSFR; classify galaxies spectroscopically and morphologically in different green valley samples. We found that by selecting the green valley galaxies based on UV or optical data, we obtain different types of galaxies in terms of their stellar masses, luminosities, SFRs, morphological and spectroscopic classes..