【Objective】The objective of the current study was to investigate the occurrence of diseases and insect pests of the ancient and famous trees in West Lake scenic area in Huizhou， and to provide reference for their scientific conservation and management. 【Method】The main diseases and insect pests in the old trees and the grade of damages caused by them were investigated using methods of general investigation and random inspection and referring to the relevant literatures.【Result】Thirty-one old trees corresponding to 9 species， 8 genus， 8 families were found in West Lake scenic area. Twelve kinds of diseases， identified in these trees， which damaged leaves of old trees were Cercospora Sojina Hara， anthracnose， brown patch， Cephaleuros spp， sooty blotch， while the diseases which damaged stem were branch rot and dry rot. Nineteen species of insects corresponding to 14 families of 6 orders were found in scenic area， of which， the piercing and sucking type insects were Gynaikothrips uzeli Zimmermann giantcoccid， Tessaratoma papillsa Drury， Macrohomotoma sp.， sphingidae， Parosa sinica M.， Sylepta derogata Fabricius， Latoia lepida （Cramer）， etc， while the insect-pests which damaged the stem were Coptotermes formosanus Shiraki， Glenea cantor Fabricius， Batocera horsfieldi （Hope）， etc. The degree of damages caused by leaf diseases， piercing and sucking type of insects and leaf-feeding insects was lesser， while the diseases branch rot， dry rot of stem and root， and insect-pests Coptotermes formosanus Shiraki caused serious damages on trees. 【Conclusion】It has been recommended to aware the people for the threats of endangering old plant species， protection of the old trees， enhance rejuvenation and control measures for diseases and insect pests， improve plants resistance to disease and insect pests and application of scientific techniques to prevent and control disease and insect pests for ancient and famous trees.