This study developed a non-biodegradable membrane from ultra-thin titanium foil,for use as a guided tissue regeneration membrane in dental implants. The etching behaviors of ultra-thin titanium foils in concentrated sulfuric acid are studied and the effects of surface modification on in vitro bioactivity determined as well. Experimental results indicated that the degree of acid-etching of ultra-thin cpTi foils could be controlled by varying the H2S04 concentrations. The concentration should be between 40% and 50% to maximize weight loss. Scanning electron micrographs of acid-etched titanium surface revealed a uniform distribution of very small (3-4μm) peaks and valleys,and machining of the titanium surface yielded typical microscopically grooved surface characteristics. Surface roughness increased with the acid concentration and was strongly related to the weight loss. Etching ultra-thin cpTi foils in > 30% H2S04 drastically increased the XRD intensity of TiH2， as revealed by the changes in weight loss and surface morphology. The results of the cell culture indicated that neither untreated (CP-Ti) nor treated(AE-Ti) foils were cytotoxic to cells. The morphology of cells on the AE- Ti surface was superior to that on the CP- Ti surface. The results of the tissue culture established that AE- Ti promoted cell migration and repaired damaged bones more effectively than CP- Ti. More bone-like nodules were formed on AE- Ti foil than on CP- Ti foil. Results of this study demonstrate that etching with concentrated sulfuric acid is an effective means of modifying the surfaces of ultra-thin titanium foils and enhancing inνitro titanium bioactivity