Many reports have been published on the tissue damage of a shock wave with respect to histopatological changes in light microscopy and various imaging modalities. However, the studies on the electron microscopic finding and cause of renal functional change such as parenchymal obstructive pattern following extracorporeal shock wave lithotripsy (ESWL) have not been elucidated. In order to evaluate the microstructural changes after shock wave exposure, gross, light microscopic and trasmission electron microscopic findings were asnalyzed with rabbit kidneys. Preliminary study (n=2) was performed to determine the dosage intensity of shock waves to inflict damage, usign a EDAP LT 01 piezoelectric extracorporeal shock wave lithotriptor. A shoke wave of various intensities were given to the left kidneys of 3 different groups of rabbits. Storage value of 100, 50, 25 at rate of 20/sec under 87% power were given to group I (n=4), group II (n=4), and group III (n=3) respectively. The right kidneys were preserved as the control group. The rabbits were killed 6-12 hours later. In gross, there were a few subcapsular hemorrhagic foci and mild congestion of corticomedullary junction without a large hematoma formation. No significant differecnes were noted between each group. Light microscopic findings were mainly hydropic changes in the proximal convoluted tubules and congestion without significant necrotic changes. The observed pathologic changes in the transmission electron microscopy were vacuolization of cytoplasm with swelling of epithelial cells especially porximal convoluted tubules. There were also tubular obstruction due to swelling and desquamation of epithelial cells into tubular lumen. The structural changes of intracellular organelles were not found at storage values of 25 and 50. But dilatation and structural alterations of endoplasmic reticulums were noted at value of 100 with cell membrane structural change of intracellular organelles is one cause of renal functional change such as parenchymal obstructuve pattern after ESWL.