The charity said some countries have not responded generously enough and must announce new donations at today's donor conference in Geneva.
As Britain's Disasters Emergency Committee (DEC) announced that more than £25 million has now been pledged by the public to their Asia Quake Appeal, UN Secretary-General Kofi Annan invited ministers to attend the conference in Switzerland. He warned more death could sweep the region if extra aid was not received soon.
The earthquake on October 8 killed tens of thousands in Pakistan and India and left thousands more injured. With temperatures set to drop further as snow sets in over the coming weeks, aid agencies say the need for shelter and medical supplies is increasingly desperate.
The DEC urged the Geneva delegates to fully finance the required aid effort as they announced the millions raised by the British public.
DEC chief executive Brendan Gormley said: "Once again people across the UK are leading the way through their generosity online, by the emergency phone lines and by post.
"We need them to continue to give, as more money is desperately needed."
Research for Oxfam revealed that the UN appeal for 312 million (£175 million) in aid is more than two-thirds away from its target, with only 90 million (£50 million) pledged so far.
Individual contributions were gauged according to the relative size of a country's economy as a proportion of the OECD total.
Only four countries - Sweden, Luxembourg, the Netherlands and Denmark - have given more than their fair share, the charity claimed.
The US, Italian, German and Japanese governments have all given less than one-fifth of their share, and governments in Belgium, France, Austria, Finland, Greece, Spain and Portugal have so far contributed nothing at all.
Oxfam said that although some of these countries might have given resources outside the UN's fund it was vital to ensure that the organisation's appeal was also met.
Phil Bloomer, the charity's policy director, said: "Governments are once again failing to respond to an emergency appeal. The logistical nightmare in Pakistan is bad enough without having to worry about funding shortfalls as well.
"Governments meeting in Geneva today must put their hands in their pockets and pay their fair share. The public will be shocked that so many rich governments have given so little."
The appeal following the Boxing Day tsunami was 80 per cent fulfilled within 10 days but the low amounts pledged for this latest disaster were not unusual, Oxfam said.
A black hole of 1.3 billion (£730 million) in emergency programmes occurred in 2004 after donor governments failed to give enough to the UN's appeals, and similar figures were also recorded in 2003.
Oxfam are urging the creation of a global emergency fund that will plug the gaps and be in a position to deliver aid immediately.
Mr Bloomer said: "The slow response to the UN South Asia appeal is depressingly familiar. These delays can cost thousands of people their lives. What will it take for rich countries to learn this obvious lesson?
"Until a one billion dollar fund exists, the chaotic passing of the begging bowl will go on and people who survived disasters will continue to die while they wait for aid."
The UN Global Emergency Fund has already been approved by world leaders and will go before the General Assembly for ratification in November.
Hilary Benn, the International Development Secretary, warned EU member states yesterday that the relief effort for victims of the earthquake was a "race against time" as winter approached. Speaking at a meeting of EU development ministers in Leeds, he urged them to do more to help.
Later today Mr Benn will attend the emergency meeting of international donors in Geneva hosted by the UN Secretary-General, where he says he intends to press the UN to make faster progress with the relief effort.
Britain has pledged £33 million so far in relief and organised 14 relief flights and three heavy-lift Chinook helicopters. The Department for International Development says Britain is the biggest European donor to earthquake relief by far.
Jemima Khan, the Unicef UK ambassador and former wife of politician and ex-cricketer Imran Khan, said yesterday that no amount of aid following the earthquake could be "satisfactory".
She said: "It is such a massive disaster that nothing is going to be satisfactory. There are some three million people left homeless, so although the response might have been adequate so far so much more needs to be done to help protect people.
"Help is particularly needed to protect children because so many have been orphaned."