To analyze the chemical composition of volatile oil of macadamia ternifolia flowers and provide the scientific proof for further exploitation, the volatile oil was extracted by supercritical CO2 fluid in this paper. Their compositions and relative contents were quantitatively determined by GC-MS with peak area normalization method. Results showed that 50 chromatogram peaks from volatile oil of macadamia ternifolia flowers were isolated, and 43 volatile compounds were identified, which was accounted for 87.09% of total volatile compounds. These compounds included alkenes (2.66%), alcohols (18.44%), phenols (0.78%), aldehyde (13.91%), ketone (3.60%), esters (7.20%), acids (21.74%) and alkylene oxide (9.54%). The predominant volatile components were phenethyl alcohol (8.75%), 4-hydroxybenzaldehyde (6.88%), trans-linaloloxide (6.25%), phenylacetic acid (5.94%), α-phenylmethyl benzeneethanol (4.22%), benzyl alcohol (3.75%), cinnamic acid (2.19%), ethyl phenylacetate (1.72%), linalool (1.25%).