PURPOSE: To prevent residual pollution due to a net-like body and outflow loss of vegitation materials by holding vegitation bag bodies and seeds on the net-like body made of strength rayon or preservatively treated corrosive material.

CONSTITUTION: Plant seeds 5 are stuck on a net-like body 1 using strength rayon such as polynosic rayon or preservatively treated corrosive raw material, and vegitation bag bodies 6 receiving fertilizer and the like are mounted on the body 1 at regular intervals. Next, this vegitation base body N is layingly provided on the face of slope, and the strength of the net 1 is maintained during the term from a half year to two years up to germination and development of plant, so as to prevent outflow loss of the vegitation materials. Next, as the plant is developed and grown to some extent, the net 1 is gradually decomposed and corroded to be homogenized to the soil. The seeds 5 are stuck on a sodded body or a mat consisting of soluble raw material and this can be stuck on the net 1, without directly sticking seeds 5 on the net 1. Hereby, the strength can be held during the term required for protection of slope face and development of the plant so as to prevent outflow loss of the vegitation materials, and residual pollution due to the net-like body can be prevented.