Abstract: Based on the monitoring results of ecological environment monitoring network in Heilongjiang Province,the changing characteristics of ecological environment quality in Heilongjiang Province during the 13th Five-Year Plan period were summarized,and the ecological environment quality status during the 14th Five-Year Plan period was predicted by using Random Forests and GM (1,1) prediction model.The results showed that during the 13th Five-Year Plan period,the environmental quality of air,water and sound in Heilongjiang Province improved comprehensively.The annual average values of ambient air main pollutants,including PM_2.5, PM₁₀, SO₂, NO₂ and CO,showed a significant downward trend,and the annual average values of PM₁₀, SO₂, NO₂ and CO in "Ha-Da-Sui" Key Area showed a downward trend.The quality of surface water showed a fluctuating trend,and the water quality conditions were all mildly polluted.During the 14th Five-Year Plan period,the ecological environment quality in Heilongjiang Province would be in a stable performance with good momentum trend; and the annual mean values of main pollutants in ambient air and main pollution indexes in surface water would show an obvious downward trend,and the environmental quality of road traffic sound would be further improved.