"The issue is not the level of prices, but the duration," Ifzal Ali told Reuters in an interview.
"For example, $40 a barrel sustained from now to the end of 2005 would be far more painful than the $50 price" lasting for two quarters, he said.
Crude oil prices have fallen nearly $6 from last week's record highs of $49.40 a barrel for US light crude, but concerns over economic damage from high oil prices persist in Asian countries, some of which are large oil importers.
Ali, in Tokyo for the launch of an ADB report, said rises in oil prices would affect Asian countries differently depending on the country's macroeconomic policies and what stage of the business cycle it was in.
For instance, high oil prices could hurt Asian economies through deterioration in trade balances by raising import values. Inflationary pressure from higher oil prices could also force interest rates to rise more quickly than expected, and indebted countries could find themselves stretched.
"Initial conditions are very important. It's (about) how fragile the economy is before the oil shock," Ali said, adding that the Philippines and Indonesia would be most vulnerable.
"You may ask why Indonesia it is a net energy exporting country," Ali said.
"What is happening is that its domestic fundamentals are very fragile," he said, adding that even if Indonesia's trade balance improved due to energy revenues, it could not escape inflation pressure, which could trigger an interest rate rise.
If higher oil prices hurt economic conditions in Group of Seven nations, Indonesia's exports to them could also suffer, Ali said.