The move will see the income threshold more than double
More than a million extra people in Scotland will soon be eligible to claim financial help for the cost of civil court cases.
Justice Secretary Kenny MacAskill said changes in legal aid rules were the latest in a series of steps to help hard-pressed families and businesses.
From next spring, the upper disposable income threshold for civil legal aid will more than double, to £25,000.
The Law Society of Scotland welcomed the changes but requested more details.
At present, less than half of all people in Scotland could potentially apply for legal aid in civil actions such as divorce proceedings, child custody cases and employment tribunals.
But the new measures will make three-quarters of the population eligible to seek free or subsidised legal aid.
Their disposable income will be a key factor in whether or not they get legal aid.
Currently, people with an annual disposable income of £3,156 a year or less pay no contribution towards their legal costs, while those with a disposable income of up to £10,306 make a contribution.
The changes will mean that that upper threshold is increased to £25,000, with a tapered system of contributions for those with annual disposable incomes of between £10,306 and £25,000.
Mr MacAskill said: "I have long considered it unfair that people of relatively modest means can find themselves unable to pursue a complex and expensive legal action.
"As a first step towards correcting that unfairness we will increase the financial eligibility limits for civil legal aid with an appropriately tapered contribution regime.
"For the first time in many a year, legal aid is being rolled out, not rolled back."
He said the Scottish Government was also working with the Scottish Legal Aid Board to bring forward simplified and increased fees for civil legal practitioners.
Oliver Adair, from the Law Society of Scotland, said it supported "any initiative which extends access to justice".
But he added: "We would like to see more details of the financial eligibility, in particular the contributions levels people will have to pay, to evaluate how the changes outlined in today's announcement will help more people access legal aid."