Using different types of proximity potentials, we have examined the trend of variations of barrier characteristics (barrier height and its position) as well as fusion cross-sections for 50 isotopic systems including various collisions of C, O, Mg, Si, S, Ca, Ar, Ti and Ni nuclei with the 1 ≤ N/Z < 1.6 condition for compound systems. The results of our studies reveal that the relationships between the increase of barrier positions and the decrease of barrier heights are both linear with the increase of the N/Z ratio. Moreover, fusion cross-sections also enhance linearly with the increase of this ratio.
