Magnetic properties of c-axis uniaxially in-plane aligned Ba-ferrite thin films were studied, Ba-ferrite thin films on [110] a-plane single-crystal sapphire substrates were deposited by low-power RF diode sputtering, Different degrees of grain isolation were achieved via postdeposition annealing at various temperatures in a rapid thermal annealing furnace, In this study, a magnetic evaluation of intergranular interaction was carried out using the well-established remanent magnetization Delta M curve. The results presented indicate a positive magnetostatic interaction, the strength of which is correlated with grain separation when measured along the magnetic easy axis direction, A predominant negative magnetostatic interaction was observed when measured along the magnetic hard axis direction, the magnitude of which is relatively independent of further grain separation.