Sen. Barry Goldwater (R-Ariz.) has put aside thoughts of political retirement and intends to seek a fifth term in the Senate, sources told the Associated Press yesterday.

A Goldwater aide said the senator had scheduled a mid-afternoon news confernce for today at his home in Paradise Valley, Ariz. The aide said she didn't know what Goldwater intended to announce.

But one source said "I'd be surprised if he doesn't run. I feel pretty confident he's going to." A second source said, "everything he's done in the last few months" points to the veteran Arizona senator seeking a new term.

The 71-year-old Goldwater, who was the Republican Party's presidential nominee in 1964, has been saying for months that he might retire when his term expires next year.

But with the Republican Party hoping to make substantial gains in the Senate in the 1980 elections, the veteran lawmaker has been lobbied publicly by his GOP colleagues to seek a new term.

All of the Senate's Republicans except Sen. Jesse Helms (R-N.C.) wrote Goldwater and Sen. Jacob Javits (R-N.Y.) last year urging them to seek reelection. Also, the National Republican Senatorial Committee said polls showed both men could win new terms.

Larry McCarthy, communications director for the GOP senatorial committee, predicted the race for Goldwater's seat would be "a toss-up if he doesn't run. If he does we think it's a safe seat."