As many as 16 patients with nephrotic syndrome (NS) of varying etiology and 10 patients without the NS were examined for ultrastructure of lymph capillaries of the kidney. Many-staged changes, from regenerative to destructive ones, associated with proteinuria growth and formation of the NS were revealed in lymph capillaries of the kidney. Patients with the NS of long standing manifested irreversible destructive processes--destruction of the capillary walls, karyopyknosis and cytoplasm coagulation. Microcirculatory disorders may be regarded as one of the mechanisms implicated in nephropathy progress.