Conformal invariance of the D-particle effective action

It is shown that the effective theory of D-particles has conformal symmetry with field-dependent parameters. This is a consequence of the supersymmetry. The string coupling constant is not transformed in contrast with the recent proposal of generalized conformal symmetry by Jevicki et al. [A. Jevicki, T. Yoneya, Nucl. Phys. B 535 (1998) 5072 (hep-th/9805069); A. Jevicki, Y. Kazama, T. Yoneya, hep-th/9810146]. This conformal symmetry can also be generalized to other Dp-brane systems.