In 16 eyes, intra-capsular cataract extractions were carried out with the aid of enzymatic zonulolysis. The following results were obtained: (1) With the application of α-Chymotrypsin and an improvemont of the operation method, the cataract extractions were carried out more easily and complications were also diminished. (2) In cases of cataract over 40 years of age and in traumatic cataracts, the expression method was principally preferred. If the lens still cannot be expressed out 5 minutes after injection of the enzyme, it is necessary to extract the ions with an aid of capsule forceps. (3) In cases ranging from 19 to 40 years of age, it was very difficult to deliver the lens within five minutes after injection of the enzyme by expression method. In those cases, the sliding method was applied successfully.