In this thesis, synthesis condition on the structural, magnetic and electrical properties of La 0.7 Ba 0.3 CoO 3 cobaltite have been investigated using XRD, Ac susceptibility and resistivity measurements. Samples have been prepared by sol-gel and EDTA method.. Also, some of samples were sintered in oxygen. In the first part of this project the effect of pH on the structural and magnetic properties of La 0.7 Ba 0.3 CoO 3 were investigated. The The temperature dependence of the real and imaginary parts of susceptibility, showed that the samples which were prepared by sol-gel and EDTA method, showed a transition from paramagnetic to ferromagnetic clusters. It means that, these materials does not have long range ferromagnetic order because they form from clusters. Such behavior has been seen in other cobaltites and results are in agreement with articles. IN one of the samples two peaks in Ac susceptibility have been observed. One in high temperature, near the curie temperature and the other in lower temperature. The first peak refered to phase transition from paramagnetic to ferromagnetic clusters and the other refered to phase transition from ferromagnetic clusters to glassy clusters.The rapid fall of Ac susceptibility with temperature in the ferromagnetic state can come from increase in anisotropy energy density on cooling below curie temperature. Such behavior has not be seen in other samples, maybe because of sintering condition, amount of oxygen ,… . I n order to found the result of this behavior samples were cooled with different rate. In order to study the traort properties of the samples, temperature dependence of resistivity have been measured. Insulator-like behavior has been appeared with decreasing temperature. Kay words: Cobaltite, Ferromagnetic clusters, AC susceptibility, Sintering, pH.