Abstract: Semi-dynamic phenol toxicologic simulation test has been conducted. Results showed that when phenol concentration (cp) in water wa above 600 mg/l, the hyacinths died in a few days; when cp was higher than 40 mg/l, the growth of hyacinths slowed down to various extents, with leaves and roots partially or totally damaged, and the chlorophyll content, chl. a/b ratio, photosynthesis speed and growth rate all decreased successively as cp was rising. Intense sun-light aggravted the toxic effect of phenol on the plant. Phenol with concentrations lower than 25 mg/l had little inhibitory effect on the hyacinths and, with cp lower than 10 mg/l, it could actually promote the growth of the plant. It was found that phenol at lower concentration could inhibit asexual reproduction but could promote earlier blooming of the hyacinths.