Annual and quantitative trends in import plant and insect pest fauna detected during plant quarantine are summarized for the periods of 1989–1998, based on the statistics of the Plant Protection Station of Japan. Quantities of imported fresh plants has increased during these 10 years, whereas that of stored plants has scarcely changed and that of timber has decreased. Seventeen orders of pests including insects and other invertebrates have been detected during plant quarantine; seven orders (Coleoptera, Diptera, Hemiptera, Lepidoptera, Thysanoptera, Acarina, and Stylommatophora) were significantly dominant. In 1989, more than 50% of the insect pests were from stored plants and timber, consisting of mostly Coleoptera and Lepidoptera. The detection of insect pests from stored plants and timber has gradually decreased. In 1998, the insect pests from fresh plants reached more than 70% in total, because the frequencies of insect pests from fresh plants has not changed for 10 years from 1989 to 1998. The above seven orders were universally detected from fresh plants. The significance of quarantine for fresh plants is discussed.