The crop climatic productive potential in the Northwestern Liaoning was assessed based on daily mean temperature and precipitation data from 23 meteorological stations from 1961 to 2010 and Thornthwaite Memorial Model, linearity analysis, and Mann-Kendall test were used for the calculation. The spatiotemporal variations of the temperature, precipitation and climate productive potential were analyzed, while the impact of climate change on agricultural climate productive potential was studied. The results showed that the annual mean temperature increased at a rate of about 0.28℃·10y~-1(P<0.01)with the annual mean temperature series altered significantly in 1987. In the nearest 50 years, the annual precipitation fluctuated with both time and spatial distribution. 82.6% of the region had a decreasing precipitation. The spatial and temporal distribution of climatic productive potential followed the same trend as precipitation. However, it was not varied dramatically on time scale. The region which climatic productive potential declined accounted for about 43.5%. Temperature and precipitation were two major influence factors for climatic productive potential, where linearity formed as precipitation performed as predominant aspect. The climate productive potential boosted at warm and wet condition while diminished under cold and dry situation. In 50 years, the grain output and climatic productive potential did not form a consistent pattern. However, they both fluctuated similarly in a large extent. Also, climatic efficiency increased every ten years. The area of interest still has room for growth at optimal weather condition.