Using conventional ceramic procedure and cheap raw materials, we have succeeded in preparing narrow linewidth polycrystalline Li-ferrites with the chemical formula: Li0.5(1-x+y)ZnxTiyFe2.5-0.5(x+3y)-zMnzO4in the region of and observed the growth condition of the grains. The performances obtained are: Gs, Oe, Tc=104-147°C, . The effect of the preparation technology and the composition was discussed. The results show that the growth procedure of the grains is closely related with the distribution of the particle sizes of the powder. The experimental results show that this ferrite is suitable for applications in some microwave devices, such as low power circulators, due to its good performances and low cost.