Abstract: The microstructure characteristics and the precipitates of low carbon strips were researched by optical microscope,scanning and transmission electron microscope.The strips used in the experiments were produced by Flexible Thin Slab Rolling (FTSR) technology of Tangshan Steel Company,and the mechanical properties and formability of the strips were analyzed.The results show that the microstructure of ultra thin low carbon strips produced by FTSR technology consist of uniform fine ferrite and a little pearlite,and the diameter size of the ferrite is about 7.0 μm.The general mechanical properties and formability of the products are excellent,and also,the high density dislocation and a small quantity of precipitates existed in the microstructure are useful to the properties of the strips.