The shear crack jog should be open at the time of shear crack growth and propagation, of which the shear slip velocity varies in the very wide range from µm/s to km/s, suggesting that fluid pressure in the jog should decrease rapidly by small amount of fluid influx from the surrounding matrix. Thus, it seems that albite and quartz are highly oversaturated in the jog, thereby being consistent with the occurrence of dendritic quartz and ameboid-shaped albite in the jog. On the other hand, the boundary surface of the low-fluid pressure jog experiences the decompression breakout forming systematic dent structure. On the other hand, the size of large shear crack is possibly enlarged by dissipation of strain energy derived from formation of microcrack cluster and fluid flow into shear crack. Based on the dissipation, the jog density wave appears in the shear crack growth process by numerical simulation. In addition, it is shown that the shear crack interface in the ductile materials appears to be the characteristic waveform obtained by neutral stability condition of Kelvin–Helmholtz instability.