Web service is a computer program that can process human thought and knowledge to provide a specific piece of information. Web service is used by the traffic police and the public to give information of vehicle ownership. The purpose of this research is to build a web sevice as a tool to conduct a search of the motor vehicle owner information appropriately. Web service created using Microsoft Visual C-Sharp or better known as Visual C # as the programming language. The process of working on the web service is based on the data user to surf the motor vehicle certificate contained in the web service using Android devices. Users to request information about motor vehicle using an Android device to send vehicle number as the key. Request is sent in the form of a web service SOAP messages that can interpret the content of messages sent by users. Information on the results of searches done web service will be sent back to the user (android device) in the form of a SOAP message, as such information can be displayed on the vehicle data android device. With the web service, users especially the traffic police and the community in general is expected to accelerate the vehicle ownership information.