  We investigate the Hawking radiation of Schwarzschild-de Sitter (SdS) black
hole by massive particles tunneling method. We consider the spacetime
background to be dynamical, incorporate the self-gravitation effect of the
emitted particles and show that the tunneling rate is related to the change of
Bekenstein-Hawking entropy and the derived emission spectrum deviates from the
pure thermal spectrum when energy and angular momentum are conserved. Our
result is also in accordance with Parikh and Wilczek\rq s opinion and gives a
correction to the Hawking radiation of SdS black hole.
