摘要:Phnom Kulen National Park, in north-western Cambodia, has huge richness in biodiversity and medicinal value. One hundred and ninety-five (195) medicinal plant species were collected from the national park to examine allelopathic potentials by using the sandwich method, a specific bioassay for the evaluation of leachates from plants. The study found 58 out of 195 medicinal plant species showed significant inhibitory effects on lettuce radicle elongation as evaluated by standard deviation variance based on the normal distribution. Three species including <i>Iris pallida</i> (4% of control), <i>Parabarium micranthum</i> (7.5% of control)<i>,</i> and <i>Peliosanthes teta</i> (8.2% of control) showed strong inhibition of lettuce radicle elongation less than 10% of the control. The results presented could present as a benchmark for isolation and identification of allelochemicals among medicinal plants used in Cambodia.