Abstract: To analyze the chemical constituents of essential oils of the leaf,stem and fruit from Acer palmatum cv.atropurpureum and study their biological activities.The volatile oils were extracted by supercritical CO2 extraction and were separated and identified by GC-MS.Their antiviral activities in vitro were inspected.99 components were identified in which main constituents were methoxy phenyl oxime (28.64%),toluene (19.12%),octacosane (16.26%),(Z)-3-hexen-1-ol (8.94%),n-hexadecanoic acid (7.08%),di-sec-butyl ether (9.18%) from the leaf volatile oil,octacosane (16.28%),3,7-dimethyl-1,6-octadien-3-ol (8.00%),2,4-bis(1,1-dimethylethyl)- phenol (6.75%) from the stem volatile oil and 1,1-diethoxy-ethane (16.56%),methyl cyclohexane (15.56%),2-ethoxy-3-chlorobutane (14.79%),octacosane (11.12%)from the fruit volatile oil.The volatile oil of the leaf,stem and fruit extracted by cyclonexane and aether showed special inhibiting activities against some viruses. Chemical compositions of the volatile oils of the flower,leaf and stem showed significant differences and different antiviral activities.