Abstract: The occurrence of Citrus Huanglongbing were investigated to reveal the epidemic diffusion in citrus orchards. Based on the three types of treatment: natural conditions without artificial control, simple pest control and disease prevention and the integrated control methods, we established the epidemic diffusion model of Citrus Huanglongbing by the dynamic inspection of onset and dispersion in Huangyan District from2002 to 2007, with the help of the epidemic census data: P₁=12.9690N₁-18.10（n=6，r=0.9945**）or P₁=0.2293N₁²+11.135N1-14.89（n=6，r=0.9948**），P₂=7.8857N2-10.2667（n=6，r=0.9675**） or P₂=1.4107N₂²-1.9893N₂+2.90（n=7，r=0.9996**） and P₃=-0.1398xN32+1.1248N₃-1.141(n=6,r=0.8396*). The results show that it takes nine years from the onset to complete destruction in natural conditions without artificial control by the models. Simple pest control and disease prevention measures also were difficult to achieve the sustainable control effect. The integrated control methods’s an effective approach to control Citrus Huanglongbing sustainably and safeguard the smooth development of dominant citrus industry.