We focus in this paper on the causes of global economic and financial crisis in 2008 from the viewpoint of the crisis & business cycle theory approach originated by Marx & Kozo Uno. Our conclusion is as follows. American economic prosperity accompanied with the global synchronous prosperity was brought about by superabundant inflow of funds from foreign countries such as mainland China, Europe, Japan and so forth, easy credit policy by FRB, and increased fiscal spending, all of which led to US housing bubble and expanded consumer spending. However, overheating of the global and/or US economy incurred both the bottle-necks in the supply of petroleum, natural resources, grain etc. and the stringency of the labor market. These factors could give rise to an inflationary acceleration in the US economy. To prevent this, FRB began to raise Federal Fund rate successively. On the other hand, profit of US industries reached its peak in 2006 and began to decline since the next year because of a rising trend in unit labor cost and the other unit non-labor costs. It is noteworthy that the declining trend of profit in US industries had began prior to the Rehman Schock in September 2008. The raising of FF rate by FRB necessarily reversed US economy into a recession, but it also invited the collapse of its housing bubble. These results were quite critical: consumer spending decreased abruptly, prices of securitized commodities declined suddenly, sellers of protections in Credit Default Swapping dealing went almost bankrupt and, therefore, many major financial institutions underwent a failure of management, suffering a huge loss. The peak of a series of crises was when Rehman Brothers went bankrupt. Most financial institutions would no longer lend money to other financial ones. Such a massive credit crunch made it impossible for investors and consumers to buy production goods and consumer goods. These economic and financial crises brought about global crises through four channels: credit crunch, a pullout of capital from developing countries, an excessive reduction of import from the US and a global synchronous free fall of stock prices. For the time being, these crises have come to an end, but economic recovery in US and the other advanced countries seems very slow and fragile, as is shown in the case of Dubai shock and Greece fiscal crisis. We must pay attention from now on to the US and the other global economy.