Under the condition of continuous data, the stability and representativeness of parking demand characteristics index was investigated. The stability and representativeness of parking demand characteristics index based on the continuous data analysis is quite different from the assumptions in the traditional application process. It is shown that there are some defects in the previous empirical random sampling and processing methods. However, the group differences were effectively suppressed after the peak ratio conversion of parking demand characteristics index. By simultaneous statistical inference technique, there is no significant difference between each group among all parking demand characteristics indexes tested, which suggests that the parking demand characteristics index has the stability and representativeness within the fluctuation range of each index.