Hewlett-Packard was the leader of computer for many years but losing its core-competence recent years, this thesis is trying to study the root cause internally based on the strategy management perspective. From external marketing environment to internal functional level analysis to support the key reason on Hewlett-Packard strategy management issues. In the competitive market of computer industry, We can see the old companions like Dell and Sony are no longer as profitable as they were used to be, Dell has gone off market since 2013, and Sony announced they will leave the PC market. In this thesis, we divide chapters into functional level strategy and business level strategy to demonstrate how HP is cope with current trend and what decisions have been made. Hewlett-Packard is gradually losing its competitive strength due to several reasons. For instance, R&D design products with less innovation but cost-oriented, marketing do not position product as premium product in the market, and supply chain controls inventory less efficiently.