Poly (ethylene terephatate) (PET) waste materials were depoly-m erized by ethylene glycol under the selecting reaction conditions. Bis (2-hydroxyethyl) terephthatate (BHET) content of the resultant was considerable. The resultant was easily purified. The etherification reaction of ethylene glycol was also restrained. BHET was polymerized to give poly (ethylene terephatate)
the quality index of which was up to standard. The spinnability of PET was better.