Central venous catheterization (CVC) is performed frequently in clinical practices in Operation Rooms(OR) and Emergency Rooms(ER). CVC is performed for different reasons such as supply nutrition or medicine. For CVC ultrasound (US), diagnostic device is preferable among other medical imaging technologies. Central Venous Catheterization (CVC) under the 2D US guidance requires skills for catheter placement to avoid damaging non-targeted blood vessels. Therefore, there is a great need for improvements in the CVC field where mechanical complication has a risk of occurring during the procedure, for example misplacement of the needle. This master thesis project was performed at Kyushu University department of mechanical engineering and collaboration with Maidashi Kyushu University Hospital department of Advanced Medicine and Innovative Technology in Japan. This thesis is aimed to develop a new simple and cheap guidance system for CVC placement. The system performed on a Tablet PC and will be using already existing Ultrasound machines in Hospitals and Augmented Reality(AR). The project developed a simple AR-System for CVC placement with use of the ArUco library. The new developed system takes information from Ultrasound images and constructs a 3D-model of a vein and artery. Then the 3D-model is augmented on the patient through the tablet PC by using the ArUco library. The construction and augmentation is all performed on the tablet PC and has a small computation to complete the necessary procedures for the 3D-blood vessels. The AR-system has a simple control where the interface of the system is a simple push and action system. When a good visualization of the blood vessels and Doppler effect is shown on the ultrasound machine, the surgeon presses the screen and the image is saved. After about five images are acquired, the system builds the 3D-model and augments it on the patient using a marker. For the development of this system it implemented the waterfall method where each step was tested and checked, before moving to the next step. A full functional system was developed and tested. From the tests performed it is shown that there were limitations due to segmentation and depth perception. But the system has possibilities as an aid for CVC placement.