This study is aimed to explore the topic of discrimination of "Pricing on Peak and Off-peak Periods (PPOP)" in the national freeway Electronic Toll Collection (ETC) for the government cooperated with the private sector, in order to achieve the goal of financial self-liquidating. Fist, this study established the demand model, total variable cost function, and the benefit function. Second, while the PPOP scheme was adopted on the freeway, the user's switching probability was combined in the above demand model. The standpoint of the financial breakeven also was employed in the financial model of the PPOP. Furthermore, the optimal freeway tolls and the payback periods are further estimated under the objective of maximum social welfare. The empirical results show that the basic toll (i.e. the offpeak period pricing) based on the PPOP is lower 13%∼28% than that without the PPOP. However, by adapting the strategy of PPOP the period of pay-back will be reduced about 4-8 year. Finally, the result shows that under the same financial conditions, the level of social welfare of the toll of PPOP will have more 3.2%-8.6% than those of the constant toll. This means the toll of PPOP posses the significant economic benefit.