Project stakeholder management (SM) as one of the building blocks for project management theory has been studied by many scholars, and a lot of theoretical frameworks are developed to analyse relevant stakeholders based on different groups of attributes to formulate appropriate expectation managing strategies. Nevertheless, contemporary research rarely describes the dynamic change of stakeholder relationship during the course of a project and mainly focuses on public-private partnership projects where the relationships are complex and some external stakeholders can be threatening to project goals. As a result, private engineering procurement projects are less addressed by such studies, in which stakeholders are usually aligned on organisation-wise objectives but they lack alignment on whose expectation to prioritize by project operation team.  This thesis studied one engineering equipment procurement project took place at start-up company who specialised on green energy and tailored one existing stakeholder model to analyse key stakeholder's salience development during two major project stages and to understand their behaviours, as well as the resulted impacts on project operation brought by individual stakeholder action. The study found out that stakeholders’ behaviours are well in line with their expectations from not only the project but also the organization, and stakeholder salience level can function as good guidance to steer project trajectory. Nevertheless, a proper cross-functional coordination is needed to not overshadow project genuine objective with organization-level objectives. The study also addressed other challenges pertinent to stakeholder management in private engineering project sector, in terms of stakeholder inclusion and information dissimilation, stakeholder coalition and intervention of top management. Further research is called out to be performed on this sector especially for start-up organisations that operate under rapid changing environment.