President Chavez is carrying out a programme of "21st Century Socialism"
Foreign oil firms operating in Venezuela will pay higher taxes on profits made in the country, under laws approved by parliament.
They face a 50% tax when a barrel of crude is priced at $70 or more, rising to 60% when average prices tops $110.
It is President Hugo Chavez's latest attempt to get greater control over his country's oil.
In 2006, he enacted laws making foreign oil firms hand over at least a 60% share in their Venezuelan operations.
The country has also begun nationalising its electricity, telecommunications and natural gas industries as part of President Chavez's drive toward "21st century socialism".
Oil prices are currently around $110 a barrel and income from the new tax could reach $9bn (£4.5bn) a year, according to oil minister Rafael Ramirez.
Analysts said that the move would make foreign firms think carefully before making any further investments in Venezuela, which is one of the world's most oil-rich nations.
"Their opportunities to turn a profit are diminishing," said Juan Carlos Sosa, editor of Venezuelan oil industry magazine PetroleoYV.
The tax comes months after President Chavez's nationalisation drive forced out two of the world's largest energy companies: Exxon Mobil Corp and ConocoPhillips.
Exxon is seeking $12bn in compensation from Venezuela after its oilfields were nationalised last year.
Last week President Chavez announced the immediate nationalisation of Venezuela's entire cement industry.
He said his government could not allow private companies to export cement that was needed to tackle a severe housing shortage.
The president promised they would be paid fair compensation for the forthcoming state takeover of what he described as a strategic industry.