First Minister Nicola Sturgeon has said that this week's party conference will be the "launch pad" for the SNP's Holyrood election campaign.
She said that the party intends to win the election, to secure a "historic and unprecedented" third term.
And she said that the party has the "people, the policies and the momentum" to achieve another victory next May.
The SNP National Conference takes place from 15-17 October at the Aberdeen Exhibition and Conference Centre.
Ms Sturgeon said: "The SNP are now firmly established as a major force in not just Scottish but UK politics, where we provide the real opposition to the Tories at Westminster in the absence of a united or credible Labour Party.
"This week's party conference, the biggest in the SNP's history, is the launch pad for next May's Scottish Parliament election.
"That is an election we intend to win, and win with an outright majority - something which is supposed to be impossible in a PR system but something we have already done once.
"To win a majority again will not be easy, and I take absolutely nothing for granted.
"But we have the people, the policies and the momentum to carry us forward to another election success next May."
She added: "Winning a third term would be historic and unprecedented, making the SNP the first party since devolution to win three successive Holyrood terms in office."
The party said that the conference will be the largest in its 81 year history.
Ms Sturgeon said that the party is keeping its "eyes on the prize" of a third term.
She said: "People across Scotland see the SNP as the party which will always stand up for Scotland's best interests, whether at Westminster or Holyrood.
"And people also know that we have the policies which are making a real, positive difference to families and communities right across Scotland - that is why I will be very proud to stand on our record next May.
"Our conference in Aberdeen is shaping up to be our biggest and best ever, and we are looking to send delegates away with a spring in their step as we keep our eyes on the prize of a third term."
Ms Sturgeon said the SNP would challenge Jeremy Corbyn's Labour to support their "alternative to austerity" this week.
She told the Andrew Marr Show on BBC One: "It's possible to have a fiscally responsible approach to the budget, to get the current budget in balance by 2019/20, to have debt reducing without implementing the scale of austerity that the UK is proposing."
Told her party's UK-wide proposal is unlikely to sway Chancellor George Osborne, Ms Sturgeon replied: "We'll put our case in the House of Commons and right now we're the only united, strong, credible opposition in the House of Commons.
"I know there are many Tory MPs... that are deeply, deeply uncomfortable with what is about to happen with tax credit cuts.
"So what we're putting forward is a plan that would still get the budget of the country, the finances of the country, into better shape but not do it by penalising hard-working people. We'll make that case in the House of Commons.
"A good start would be for Jeremy Corbyn, instead of as he's said they'll vote for George Osborne's fiscal charter, to vote with us and try to build that progressive majority for an alternative to austerity."
Ms Sturgeon also reiterated that she believes a second referendum on Scottish independence is "inevitable".
She said: "I've always believed, and I still believe today, Scotland will become independent and it will become independent in my lifetime.
"So if I believe that then that will only happen through a referendum so, yes, I guess I do believe that another referendum is inevitable but it's not inevitable just because I say it should happen, it will only prove to be inevitable if that's what a majority of people in Scotland want."