Robot Assisted Minimally Invasive Surgery has been successfully used in many surgical procedures. With merits of fast recovery and reduced risk of infection, it has gained favor among patients and surgeons. However, due to the confined workspace for dexterity, poor endoscopic 2D vision, and sensorless instruments, robotic surgical procedures such as suture-pulling, knot-tying and needle-driving are tedious and time consuming. Ideally, these operations would be automated, leading to faster, more efficient robotic surgery. This paper presents two knot-tying methods suitable for automation. Experimental performance is comparable to human speeds with the potential for significant speed-up.