The seasonal prevalence of Aedes albopictus (Skuse) and the temporal and spatial variation of biting density were studied in an urban park in Tokyo, Japan. Human landing collections were conducted monthly at 16 collection sites in Rinshino-mori Park from May/June to November during 2003 to 2005. Biting females appeared in May/June and the density peaked in July/August and decreased rapidly thereafter. The peak density was 12.5, 8.6 and 15.6/5 min in 2003, 2004 and 2005, respectively. There was a significant within-park variation in biting density among the 16 collection sites, ranging between 0.6 and 13.8/5 min. During June to October/November 2005 and 2006 cohorts of biting females were collected from the field, reared with a 3% sugar solution and their residual longevities were examined under laboratory conditions. Significant differences in mean residual longevity were found among cohorts collected from Rinshino-mori Park in different months in 2005. Significant differences were also found in mean residual longevity between cohorts collected from Rinshino-mori Park and an additional study park, Yacho Park, in 2006. Aedes albopictus-related risk for transmission of mosquito-borne virus in urban parks was discussed based on the product of mean biting density and mean residual longevity of biting females.