No Jiaotong Univ, Dept Phys, Beijing 100044, Peoples R China
; Acad Sinica, Inst High Energy Phys, Beijing 100039, Peoples R China
; Acad Sinica, Inst Theoret Phys, Beijing 100080, Peoples R China
By using York's path-integral formalism, we investigate the Reissner-Nordstrom-de Sitter (RNdS) spacetimes. We obtain not only the entropies of the lukewarm, the cold, the charged Nariai and the ultracold black holes, but also their first laws of thermodynamics. The entropy of the charged Nariai is given for the first time, to our knowledge.