After the previous day lead to oil prices drop, the European debt problems of the day continued oppression of the market. Investors' concerns about the financial situation in Spain to promote Spanish bond yields to rise again, and Spain to seek financial assistance to the discussions lead to rising risk aversion in the market. 

In addition, the rating agencies Moody's Investors Service 23, the prospect of Germany, the Netherlands, and Luxembourg's top sovereign credit outlook from stable to negative, and said that Greece withdraw from the euro area increased risk.

Economic data, the euro zone purchasing managers' index in July to maintain the same in 46.4, the index had six consecutive months below 50, indicate that the euro zone manufacturing activity shrinking, the economic data, further exacerbating the eurozone debt crisis concerns. 

However, the volatile situation in the Middle East and China manufacturing data to improve support for the oil, and ultimately promote a rebound in oil prices. 

The same day, Syria said that if the foreign intervention, the domestic situation, the possible use of chemical and biological weapons. Iran also warned Western countries that once foreign intervention in the Syrian situation, will be implemented in the counterattack. Heighten tensions in the Middle East caused oil supply concerns, and promote the rise in oil prices. 

In addition, China's published data show that industrial output in July was the best performance in nine months. The data are also to some extent, to boost market confidence. 

To the closing, the New York Mercantile Exchange, light sweet crude for September delivery was up 36 cents to close at $ 88.50 a barrel, or 0.41 percent. North Sea Brent crude for September delivery rose 16 cents to settle at $ 103.42 a barrel, or 0.15 percent.