LaCoO3 thin films with perovskite structure were prepared on Si(lll) substrate successfully by using an amorphous heteronuclear complex, LaCo(DTPA). 6H(2)O (DTPA, diethylenetriaminepentaacetic acid), as a precursor. X-Ray diffraction (XRD) results indicated that the crystalline sizes of LaCoO3 films grew from 17.8 to 34.3 nm with the calcination temperature increasing from 550 to 800 degreesC for 1 h and the crystalline sizes of LaCoO3 films grew from 22.3 to 25.3 nm with the calcination time increasing from 1 to 6 h at 650 degreesC. Auger electron spectroscopy (AES) depth profile analysis indicated that the composition of the thin film was homogenous with depth the interface diffusion took place between LaCoO3 layer and Si substrate. The thickness of LaCoO3 thin film depended on the concentration of the precursor solution and could be described approximately by the following equation: d = 0.580c + 0.285c(2). Scanning electron microscopy (SEM) indicated that the texture of the film was governed by the concentration of precursor solution When the concentration of precursor solution was lower than 15%, a smooth film without microcrack was obtained. The texture of the film could be modified significantly by adding polyethylene glycol (PEG). But the thickness of the film was hardly influenced by the addition of PEG.