The dynamic behavior of dislocations in heavily impurity (Ga, As, O) -doped Ge crystals was investigated as a function of stress and temperature by means of the etch-pit technique. The Ga and O impurities effectively suppressed dislocation generation from a surface scratch, while the As impurity did not strongly do so. Dislocations in Ga- and O-doped Ge crystals were supposed to be immobilized by the stable complexes formed through the impurity segregation and reaction. Remarkably, the O impurity, even at a low concentration of 10 16cm-3, induced the suppression of dislocation generation. The As impurity enhanced and the Ga impurity retarded dislocation velocity in motion. The O impurity had no effect on the velocity of the dislocations.