It is of great importance to investigate the extraction of polycyclic aromatic hydrocarbons (PAHs) in plant root apoplast solution for elucidating the mechanisms underlying root absorption and translocation of PAHs and their control. However, little information is available on the extraction of plant root apoplast solution to date. In this study, wheat was employed and phenanthrene was used as the representative of PAHs. Phenanthrene extracted from wheat root apoplast solution increased with increasing vaccum degree, vacuum time, centrifugal speed and centrifugal time. Glucose- 6-phosphate dehydrogenase (G6PGH) activity in wheat root apoplast solution was enhanced with increasing vacuum degree, vacuum time, centrifugal speed and centrifugal time. For the vacuum infiltration centrifugation extraction, the optimal vacuum degree was 70 kPa, the optimal vacuum time was 10 min, the optimal centrifugal speed was 3 068 r x min(-1), and the optimal centrifugal time was 15 min. Our results provide a more convenient and effective method for investigation on pollutant transport in plant root apoplast.