The growth and spreading of fibroblast, L929 cells, on various polymeric films prepared by the Langmuir-Blodgett (LB) and casting methods were investigated. L929 cells, which were cultivated on collagen and synthetic polymeric films prepared by the LB method, adhered and spread much more than those on synthetic films prepared by the casting method. This is explained by the fact that cell growth and cell spreading are suitable for L929 cells on the films having serum proteins that contain a high α-helix content, because LB films adsorbed those serum proteins estimated from the circular dichroism measurements of the films immersed in cell culture medium. An exponential relationship was observed from the plot of the cell density vs root mean square of roughness of the films, which is estimated by atomic force microscopy, whereas a linear relationship was observed from the plot of the spreading ratio vs the root mean square of roughness. It is suggested that the correlation between the cell growth or spreading ratio and surface roughness of the films where L929 cells were cultivated is considered to be more important than the correlation between the cell growth or spreading ratio and the contact angle of the films.