There are four principles of islamic economic. The first is PLS (profit and loss sharing). The second is halal and thoyyib. The third is zakat. The fourth is paying labor’s reward wisely. PLS is a instruments to move the riil sector in islamic economic. Interest is a instrument to move the riil sector in the general econimic now. To change the interest system to the PLS system is not an easy job. The human paradigma is a something logical and realistist. PLS is not stabil and fluctuative. The nisbah share between deposan and bank is constant and stabil, but the revenue of bank is always labil. The implementation of PLS in the syari’ah money group like bank, BMT has many problems. The first, the deposan aren’t ready. The second is the competition between many conventional bank used interest system. There is not opening in giving information about revenue that they get it. This is a factor why PLS was difficult to be implemented.