By establishing an AHP-based assessment index system and assessment model,and applying detection technology that is convenient and harmless for ancient and famous trees,this paper is significant for investigating and assessing the health state of ancient and famous trees,and protecting the limited resources. Fourteen indexes such as growth vigor,disease and pest were selected from the perspectives of overall situation,canopy,trunk and root,and AHP(applied analytic hierarchy process) was applied to define weights of these indexes. According to the results,top 3 indexes in terms of weight are tree vigor,treetop death,internal decay and hole,while the indexes with lower weight are parasitism,root damage,ventilation and permeability. On the basis of assessment model and method as well as field investigation,health grade of ancient and famous trees(A) can be obtained. By grading the health of ancient and famous trees into 3 levels,each level indicates a certain health state,so managers can take corresponding maintenance measures to develop the best ecological and social value of these trees. By establishing an AHP-based assessment index system and assessment model, and applying detection technology that is convenient and harmless for ancient and famous trees, this paper is significant for investigating and assessing the health state of ancient and famous trees, and protecting the limited resources . Fourteen indexes such as growth vigor, disease and pest were selected from the perspectives of overall situation, canopy, trunk and root, and AHP (applied analytic hierarchy process) was applied to define weights of these indexes. According to the results, top 3 indexes in terms of weight are tree vigor, treetop death, internal decay and hole, while the indexes with lower weight are parasitism, root damage, ventilation and permeability. On the basis of assessment model and method as well as field investigation, health grade of ancient and famous trees (A) can be obtained. By grading the health of ancient and famous trees into 3 levels, each level indicates a certain health state, so managers can take corresponding maintenance measures to develop the best ecological and social value of these trees.