Abstract: Different from a straight endoscope mechanism used for Laparoscopic surgery, single port access (SPA) surgery requires multi degrees of freedom endoscope mechanism. This work presents a 4-DOF bendable endoscope mechanism that employs a spring as its backbone. This design is slim-sized, lightweighted, and easy to implement a camera at the distal end. The suggested mechanism consists of two modules in which each has 2 DOF. A mechanism integration method with a small-sized camera as well as design principle the endoscope is introduced. The performance of the suggested mechanism is verified by experiments