Plaid Cymru leader Ieuan Wyn Jones has told his party its ministers are "already making a difference in government".
But he told party members in Llandudno they must accept the responsibilities and "rise to the challenge of nation building within government".
Plaid entered government for the first time with an historic pact with Labour after May's assembly election.
Mr Jones told delegates their aim now was to "shape the Wales of the future".
But the Plaid leader, who is deputy first minister to Labour's Rhodri Morgan, also said Plaid had already helped to shape the Wales of today.
"Wales wouldn't be the Wales we see today but for the existence of Plaid Cymru," he said.
"There would be no Welsh Office, no devolution, no assembly, no Welsh language legislation, no growth in the Welsh national institutions."
He criticised the "regressive unionist" Labour MPs who were against the coalition deal that put Plaid in coalition, but welcomed the policies introduced by the minority Labour government before the deal after pressure from the opposition.
"They called a halt to the hospital closure programme and they also agreed that Welsh nurses should get their full pay award. And quite right too".
Affordable housing was a priority said the Plaid leader
He argued that more could now be done with Plaid in government.
The priorities he outlined included ruling out the private finance initiative (PFI) in the health service, more affordable homes, the establishment of a climate change commission and improvements to roads and train services between north and south.
As a result of Rural Affairs Minister Elin Jones' absence on Thursday due to the foot-and-mouth outbreak, Heritage Minister Rhodri Glyn Thomas delivered the first speech to a party conference by a serving Plaid minister.
Mr Thomas warned Labour MPs not to scupper plans for Welsh language legislation under the new Government of Wales Act arrangements which allows the assembly to create its own legislation in certain areas.
Welsh language newspaper
He said a bid for Welsh language legislation would set the principle that the assembly government could introduce measures on any aspects of the language.
Mr Thomas told the conference he would not "accept attempts by MPs to try and limit measures on the Welsh language".
He also update his party on the progress being made on Plaid's election commitment to create a national English language theatre and said that he would be doing all he could to establish a Welsh language daily newspaper within the next year.
Rhodri Glyn Thomas was the first Plaid minister to address conference
On Thursday the conference discussed the potentially contentious issues of women-only candidate selection, whether the party should nominate peers, and its opposition to nuclear power stations.
On the question of nominations to the House of Lords, the party agreed to review its previous opposition.
In a speech to delegates at Venue Cymru, parliamentary leader Elfyn Llwyd repeated his wish for that rule to be overturned.
Under the Government of Wales Act, which allows the Welsh assembly to introduce its own legislation, some proposals have to be approved by Parliament.
Mr Llwyd argued that this meant the party needed voices in the House of Lords. A number of branches from across Wales also asked for the policy to be changed of placing women at the top of regional lists in the Welsh assembly election, and that policy will now be reviewed.
There has been resentment among some grassroots members that strong male candidates such as former party leader Dafydd Wigley were not in a position to be elected to Cardiff Bay last May.
Plaid also backed a referendum on the European Union treaty, with a decision on which side to support in any campaign to be made by the party's national council.