Using X-ray diffraction, electron microscopy, and differential scanning calorimetry, the structure and mechanical properties of tubes based on poly (L-lactide) microfibers obtained by electrospinning from a dichloroethane solution and designed for implantation in small diameter blood vessels during prosthetics are studied. It is shown that freshly formed microfibers have an amorphous structure and their heat treatment at a temperature of 70-160 degrees C is accompanied by crystallization of the polymer. Microfibers consist of lamellas similar to 20 x 200 nm in size, and their crystallites, the sizes of which depend on the processing temperature and amount to 25-34 nm, are characterized by the alpha-modification. The mechanical characteristics of the obtained tubes are considered.