Reasonably controlling or dispatching the charging and discharging behaviors of aggregated electric vehicles（PEVs）can provide ancillary services for a power system，and hence improve the security and economics of the system.Based on the driving pattern statistic data from the New Jersey region in USA，an economic analysis model is developed for an agent/aggregator of PEVs in providing regulation and spinning reserve services for the power system concerned，considering the optimal control of the PEVs' charging and discharging.An optimization model is developed to maximize the agent's profit while respecting relevant constraints.The revenue of the agent consists of the incomes from the regulation and spinning reserve markets，as well as the allowances for mitigating emissions，while the cost includes the battery depreciation cost and charging cost.The developed model is demonstrated with actual data from the New York Independent System Operator（NYISO）with 5000 PEVs specified，and the economic analysis result shows that the agent of PEVs can make profits by providing regulation and spinning reserve services in the electricity environment.