Abstract: Haze disaster has caused serious losses to agricultural production and evaluation of haze impact has important value and significance. To estimate the economic losses caused by haze pollution, this paper utilized demand- driven and supply- driven input- output (IO) model to estimate the monetary value of economic sectors’losses resulting from reduced agricultural output caused by PM2.5 in Beijing in 2012. The results showed that: (1) agricultural direct economic losses caused by haze were 4154.985 million RMB and agricultural indirect economic losses calculated from the demand or supply side were 5516.48439 million RMB (accounting for 13.94% of GDP in agriculture) in Beijing in 2012; (2) the total demand-driven economic losses of 13139.20404 million RMB (approximately 0.735% of the national GDP) and total supply-driven loss of 25172.72698 million RMB (approximately 1.408% of the national GDP) were caused by agricultural output loss resulting from PM2.5 air pollution in 2012. The results indicated that indirect economic losses caused by haze were greater than direct economic losses and Beijing’s regional economy might have been affected more seriously through supply-driven effects compared with the impacts caused by the demand-driven effects. The developed IO model is able to capture both direct economic costs and indirect cascading effects throughout inter- industrial production demand and supply chains and provide an alternative method for sector loss measurement with additional insights into inter-industry along production demand and supply chains.