Recent days Computer-aided design and image processing techniques are one of the most emerging useful tools for analysis of models in various medical, industrial and research areas. In medical field for the diagnosis of various diseases in vivo techniques including biochemical test, enzymatic tests are needed for continuous monitoring of patients. These diagnosis procedures are time consuming and inconvenient for patients. Therefore Computer assisted designing and image processing techniques are most promising non invasive tools for faster diagnosis and useful tool for designing of biomedical implants. In this paper portal vein was segmented from patient’s Liver computed tomography (CT) image by dedicated software. A Liver’s CT image of 38 year old Indian male patient’s was collected and by using imaged based software MIMICS (Materialise’s Interactive Medical Image Control System, Belgium) 3D model of HPV (hepatic portal vein) was obtained and Solid Work Professional (Dassault Systems Solid Works Corporation, USA) software was used for designing of normal portal vein’s 3D model and various portal vein diseased models including minor right portal vein thrombosis ( 19- 20% reduction in medial region of vein), severe right portal vein thrombosis (20-22% reduction in medial and distal region of vein), minor left portal vein thrombosis (19-20% reduction in medial region of vein, severe right portal vein thrombosis(20-22% reduction in medial and distal region of vein), left aneurysm (150-200 % increase of medial region).These models can be used for designing for implants and analysis of portal vein’s disorder like portal thrombosis, and portal aneurysm which are main cause of portal hypertension and also useful for surgeon for planning surgery and also helpful for understanding of portal vein hemodynamic (pressure, velocity, wall shear force