Until 2001, the Chinese Territory of Macao had not registered any autochthonous dengue cases, despite the abundance of Aedes albopictus (Skuse), a known vector. This work describes a bioecological characterization of the local Ae. albopictus adult population, with the purpose of estimating the receptivity of Macao to dengue introduction. In the wet seasons of 1997 and 1998 and the dry season of 1998, Ae. albopictus was the most abundant human-biting mosquito. Daily biting rates of 314 mosquitoes per person were recorded in the wet season with a reduction to 94 in the dry season. Ae. albopictus was mainly exophagic and exophilic and had a human blood index of 44%. The parity rate of field-collected mosquitoes was 57%. Daily survival rate ranged from 91 to 97%. Estimates of vectorial capacity ranged from 144 to 880, depending on what parameter values were used. These estimates indicated a great receptivity for the introduction of dengue viruses, as the 2001 outbreak came to prove.