A pectic enzyme treated pectin (PET-pectin) and a method of producing the same are disclosed. Citrus pectin solution is subjected to an enzymatic hydrolysis by using a mixed pectinase solution under an acidic condition, so as to obtain PET-pectin that is completely hydrolyzed. The PET-pectin has several biological functions, including stability of emulsification, anti-oxidation and inhibition of cancer cell growth, thereby being applied on food emulsion stabilizers, food antioxidants and compositions for inhibiting cancer cell growth and so on.