Epitaxial thin films of La0.67Ba0.33MnO3 was grown on the LaAlO3 (001) substrates using pulsed laser deposition (PLD). The thickness dependence of magnetotransport properties close correlated with the strain effect was studied. The out-of-plane lattice parameters dependence on variable thin films thickness was analyzed in detail by X-ray diffraction (XRD) data. In contrast with usual results that compressive strain enhances TC by increasing the transfer integral t0, compressive strain due to mismatch between LaAlO3 substrate and La0.67Ba0.33MnO3 film was found to suppress ferromagnetism and reduce TC. The anomalous magnetotransport of La0.67Ba0.33MnO3 thin films was explained by strain effect of colossal magnetoresistance (CMR) materials on the stability of eg orbital.