To increase energy security and reduce the dependency on imported oil,China is boosting up its effort of building up national strategic petroleum reserve while taking into account the associated costs including build up costs,purchases costs and holding costs.Since the initial aim for building Strategic Petroleum Reserve was to safeguard energy security and avoid macroeconomics losses caused by shortages in supply in the world oil market,however recently,the fears in oil market are no longer from the supply side but rather from the demand side.Oil prices uncertainties in the world oil market have been experiencing a sharp ups and down that mainly affect countries like China whose major economic growth depends on imported oil.With the new market reforms,it is important to analyse the advantages of allowing private companies to hold their own petroleum reserve site and to explore how it will affect the optimal reserve size to be held by the country.Development of renewable energies is another factor that may have affect the reserve size a country needs to hold in the future.A dynamic programming model that follows Markov Decision Process is developed and used to analyse how these oil prices uncertainties（stochastic variables）may affect the optimal reserve size at every year and each market state.A game theoretic model that study the interaction between public and private oil companies in holding the required petroleum reserve is presented to suggest how the latter two players may corporate.Moreover the development in new renewable energy resources is also discussed using a system dynamic model as they have an indirect effect in reducing energy dependency as well as increasing a country’s energy security.Empirical results of the dynamic programming model are presented to show the optimal size and the time path of the future petroleum reserve in China.The results suggested that under normal state despite of price uncertainties in the world oil market,initial fill up of reserve is 212 million barrels in 2014 with a filling rate of 50 million barrels each year,optimal size is expected to be attained in the year 2019 with 500 million barrels that is equivalent to China’s 2020 petroleum reserve plans.Currently China has only 30 days of net import therefore it still needs to increase its reserve size to the allowable 90 days of net import.We furthermore depicted the game theoretic model suggesting possible public and private payoffs that are based on joint venture ownership.The payoffs suggested all possible relationships that can exist between the two players and its corresponding effect.In addition to that the results from system dynamic model suggested that policies for renewable energies which aimed to increase the amount of renewable energy consumption and amount of electricity generation have a greater impact on reducing dependency on imported oil as well as increasing a country’s energy security.The amount of electricity that is generated from renewable energy resources has shown a dramatic increase and is expected to rise up to 30% in the year 2030.In conclusion,China still needs to fill its SPR reserve especially with low oil prices so as to minimize macroeconomic losses as well as costs associated to build-up of SPR sites.Policies that allow private oil companies to own their reserve site need to be established and reviewed over time since private companies’ site seems to play an important role to the public oil companies.This paper may be used by decision makers and planners as a guide to their decision making and planning process on how the current SPR is affected by the recurrent world energy transition background.