TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preparation (Disclosed): Amine component is subjected to thioureaizing with carbon disulfide and oxidation desulfurization is carried out, to obtain aromatic carbodiimide. Preferred Composition: The aromatic carbodiimide is of formula (I), (II) or (III). The aromatic carbodiimide contains carboxamide group, sulfonamide group, or amide phosphate group. The content of aromatic carbodiimide is 0.05-5 %mass with respect to polyester.R1,R2,R4=H, alkyl, aryl, or alkoxy;R3=carboxamide, sulfonamide, amide phosphate, hydroxy or amino;n=2 or more;R11-R18,R21-R30=H, alkyl, aryl, alkoxy, carboxamide, sulfonamide, amide phosphate, hydroxy, or amino, in which at least one of R11-R18, R21-R25 and R26-R30 are carboxamide, sulfonamide, amide phosphate, hydroxy, or amino, and adjacent R11-R18 optionally combine with each other to form ring;X1,X2=-O-, -CO-, -S-, -SO2-, -NH- or -CH2-;andL=bivalent coupling group.    TECHNOLOGY FOCUS - POLYMERS - Preferred Composition: The component derived from the carboxylic acid of polyester is aromatic dibasic acid or ester-forming derivative. EXAMPLE - 120 ml Nitric acid was dripped into 500 ml beaker, and 180 ml sulfuric acid was added. 28.3 g Triisopropyl benzene was added into obtained yellow slurry and stirred for 1 hour. The obtained slurry was flowed into ice water and filtered. The obtained yellow solid was washed using water until it becomes neutral, to obtain 37 g nitro component. 5.4 g Ammonium chloride, 56 g reduced iron, 300 ml 2-propanol and 60 ml distilled water were added into 3-neck flask, and refluxed for 1 hour. The nitro component was injected into resultant mixture and stirred for 2 hours. The obtained mixture was cooled to room temperature, filtered and washed using water. The organic layer was separated from the resultant mixture, dried and concentrated with magnesium sulfate, to obtain 30 g amine material. 23 g Carbon disulfide and 30 g amine material, 12 ml acetonitrile, and 6.8 g imidazole were heated at 100 degrees C for 72 hours. The obtained precipitate was washed using acetonitrile. The obtained 11.2 g polyurea component, 216 ml chloroform, 7.2 ml methanol, 8.6 g 30% sodium hydroxide aqueous solution, and 0.54 g benzyl triethylammonium chloride were added into 3-necked flask, 90.9 g of 12% sodium hypochlorite aqueous solution was slowly dripped and heated at 40 degrees C for 1 hour. The obtained mixture was washed using 200 ml distilled water, dried with magnesium sulfate, and concentrated, to obtain 9 g polycarbodiimide having weight average molecular weight (Mw) of 20000.