This standard specifies the terms and definitions, product classification, basic requirements, technical requirements, test methods, inspection rules, marking and packaging, transportation, storage and quality commitment requirements for cationic dye-dyeable polyester (PET) chips (ECDP). This standard is applicable to cationic dyes produced using terephthalic acid and ethylene glycol as the main raw materials, adding a third monomer (mass fraction ≥ 2.5%), and adding other monomers (mass fraction ≥ 3.0%) at the same time. Easily dyeable polyester (PET) chips (ECDP).