Engineering survey refers to all survey practices executed to support the investigation, planning, design, construction, operation and maintenance of engineering works. Because of the extensiveness of engineering survey, a diverse scope of land surveying methodologies, instruments and technologies are employed in this field. Professional land surveyors will design the best surveying scheme according to the requirements of an engineering project and deploy suitable surveying instruments and techniques to complete each surveying task. Hong Kong is a highly developed city with world class engineering infrastructure and densely built environment. Engineering survey practice in Hong Kong is not only frequent and diverse but also of high level of difficulty and demanding standards. Therefore, the participation of land surveyors is indispensable for the completion of every engineering project, for example, providing detailed topographic maps for a road construction design, ensuring a sea-crossing bridge to be built according to its designed dimension and location, controlling the drilling route of an underground tunnel accurately, monitoring the settlement of a building structure affected by excavation works, etc. The examples tell the important role played by land surveyors in every kind of engineering projects.