The invention relates to a controlled release tablet. The controlled release tablet is gliclazide bi-layer osmotic chip; one layer of osmotic chip contains gliclazide and permeation accelerate matter which are in labelled amount, the other layer of osmotic chip contains osmotic substance; the core of the controlled release tablet is coated by a semipermeable membrane containing polymer, and a small hole is formed in the side, containing active ingredients, of the semipermeable membrane.