This paper examines the uncertainties in Chinese gas markets, analyze the reasons and quantify their impact on the world gas market. A literature review found significant variability among the outlooks on China's gas sector. Further assessment found that uncertainties in economic growth, structural change in markets, environmental regulations, price and institutional changes contribute to the uncertainties. The analysis of China's demand and supply uncertainties with a world gas-trading model found significant changes in global production, trade patterns and spot prices, with pipeline exporters being most affected. China's domestic production and pipeline imports from Central Asia are the major buffers that can offset much of the uncertainties. The study finds an asymmetric phenomenon. Pipeline imports are responding to China's uncertainties in both low and high demand scenarios while LNG imports are only responding to high demand scenario. The major reasons are higher TOP levels and the current practice of import only up to the minimum TOP levels for LNG, as well as a lack of liberalized gas markets. The study shows that it is necessary to create LNG markets that can respond to market dynamics, through either a reduction of TOP levels or change of pricing mechanisms to hub indexation.