Abstract: Tn this paper the superplasticity of cold-rolled sheet metal of LF6 aluminium alloy was studied. An extremely significant superplastic effect can be attained in cold-rolled condition without any special pre-treatment. Total elongation as high as 463%. can be achieved under the following conditions:490℃ and 3.33 ×10-4s-4.The corresponding strain rate sensitivity index m = 0.68 and flow stress o=2.8 MPa. As compared with the da- ta available in the literature, the above results are in the lead at home and abroad. The results of mechanical tests and metallographic examinations indicated that the presence of the particles of second phases such as B（Mg2Al3）, MnAl6. and TiAl3 leads to the formation of fine and stable grains necessary for achieving superplasticity. The most probable deformation mechanisms for superplastic flow of LF6 aluminium alloy are grain boundary sliding accommodated by the sliding within grains. The results presented in this paper may pave the way for incorporating the pre-tre-amment necessary for superplastic forming of certain alloys in the processing of sheet products. As a result, the superplastic forming processes can be simplified and the application of the new technology to industry can be expanded. The achievements of this study have been put into practice and the results were excellent. The authors have made some suggestions to the metallorgical department in order to popularize the achievements as early as possible.