Croatian market of electric power supply until joining the EU has not been interested and open as it is today. Of course, the main reason for the huge change on the market was liberalisation of the market led by joining the European Union in 2013, which opened up the market for new entrants, meaning competition. This essay is based on strategic analysis of Croatian market, starting with the SWOT analysis of the biggest supplier, HEP ( Hrvatska Elektroprivreda), followed by SWOT of competition ( smaller companies with neglected share of customers). The main analysis is based on Porters five forces of competition, which examines the Croatian market, its significant players, threats and overall performance. In this essay, the focus is on HEP and its three main and significant competitors, Hrvatski Telekom, GEN-I and RWE. Each of this companies have already been present on some other markets or in some other sectors ( telecommunication, gas supply etc).