However, the party said that despite backing a cap in principle, it would oppose any "grubby stitch-up" by parties at Westminster in their attempt to limit party donations.
The Nationalists were responding to Margaret Curran, the Shadow Scottish Secretary, who has called on Alex Salmond to support Ed Miliband in his attempt to get a £5000 cap on party donations.
Last November, the SNP received £1m from Ayrshire couple Chris and Colin Weir, who won £161m in the Euromillions lottery. A month earlier it banked a £918,000 bequest from Scots Makar Edwin Morgan.
In a letter to the First Minister, Ms Curran stresses the Labour leader has taken a lead on party funding and says: "I am very much hoping the Scottish National Party will join the other parties in ensuring that large donors do not hold the balance of power in our politics.
"Given the momentum which is building on this issue, I would hope that you would back Ed Miliband's call for a cap on donations of £5000 so that Scotland will not be left behind in an effort to clean up our politics."
The MP for Glasgow East adds: "We need to take action to clean up party funding now and it's time we had a cap on donations. Such a cap would no doubt have a big impact on the incomes of political parties but I believe this is absolutely the right approach to take in Scotland."
However, a spokesman for the SNP told The Herald that while the party supported a cap on donations in principle, it had to apply to "all donations, from individuals and organisations, including City financiers and trade unions, in line with the recommendations of Sir Christopher Kelly's report".
He added: "We will have no truck with any attempts at a grubby stitch-up engineered by Labour and the other London-based parties, who are currently having closed-doors talks together on the issue."
Renewed pressure to cap party funding arose in March after a senior Tory fundraiser, Peter Cruddas, resigned. He had been secretly filmed boasting how he could provide access to the Prime Minister and other ministers for "premier league" donors giving £250,000 to the Conservatives.
Subsequently, talks among the main parties at Westminster resumed at finding a way forward on party funding.
At the weekend, Mr Miliband proposed the £5000 donation cap, half that suggested by Sir Christopher, chairman of the independent Committee on Standards in Public Life, and a 10th of that put forward by David Cameron.
However, the Labour leader made it clear he wanted to keep the system which allows three million trade unionists to individually give the party £3 a year. As a result, the Conservatives branded his proposal "virtually meaningless".