Research has indicated that up to 40% of small companies in Christchurch could eventually fold following the earthquake on 22 February.
The figures were presented at a seminar in Wellington last week on the role of small and medium enterprise in disaster recovery.
Massey University's Centre for Small to Medium Enterprise says small firms tend to be highly vulnerable to disasters.
Director David Deakins says studies after Hurricanes Katrina and Andrew in the United States suggest about 40% of businesses did not reopen.
The Canterbury Employers' Chamber of Commerce says 59,000 people are currently on the Government's employment support scheme.
It estimates that between 5000 - 10,000 companies in the city will have to rely on significant help in the future.
Business New Zealand chief executive Phil O'Reilly, says some businesses will be unable to stand on their own two feet unaided when the subsidy scheme phases out in the next two weeks.
He hopes that business recovery coordinators in Christchurch will be able to identify those struggling companies quickly - and help arrange further on-going support.
Mr O'Reilly says it's vital that small businesses don't lose faith.
Professor Deakins says research also shows that firms that do survive disasters, tend to do as well as or better than before the event.
He says the success of small and medium sized businesses is essential to Christchurch's survival.
