E. Blackburn Moore, 83, one of the towering figures of the conservative political structure fashioned by the late Sen. Harry F. Byrd Sr. of Virginia, died here today.

A native of Washington, Mr. Moore announced his retirement from the Virginia House of Delegates in 1967 after a 35-year career, 18 of them served in the speaker's chair. His tenure as speaker was the longest in the history of the commonwealth.

Mr. Moore was a powerful ally of the late Sen. Byrd, epousing and advancing in Richmond much of the same causes that Virginia's longtime senator nurtured through the Congress in Washington.

Mr. Moore's stature and influence as speaker of one of the oldest legislative chambers in the nation marked him as one of the political legends of the state.

So strong were his views and so impregnable his position, it became his practice, it was recalled, to appoint Republican members of the House only to committees that never met. He thus honored the rules of procedure on the one hand, and guaranteed the free flow of favored legislation on the other.

Sen. Harry F. Byrd Jr., son of the late senator, said today that Mr. Moore was "one of my closest and dearest friends.

"I regard him," the senator said, "as one of the finest and one of the most dedicated public officials to serve Virginia during my lifetime. As speaker of the House of Delegates, his contributions to our beloved state were many and his public service was totally unselfish."

Mr. Moore was educated at Davidson College and Cornell University. His home was in Berryville, Va. -- the home town of the Senators Byrd -- and he was a fruit grower, a farmer and a banker by profession.

His service in the House was in behalf of a constituency that included Clarke and Frederick counties and the city of Winchester.

He was the last of his kind in the speaker's chair. He was quiet and authoritative, and a man who one Capitol observer said could walk knee-deep through a pile of leaves without making so much as a rustle.

When he retired, he said he thought it was time "to make a change in the speakership" -- and that his wife had persuaded him that his service in the chamber he loved had run its course.

Mr. Moore presided over the House during the terms of five governors, with one of his principal legislative accomplishments being the creation of the State Water Control Board ot control pollution in the streams of the commonwealth.

After his birth in Washington, and after he had completed his education, Mr. Moore settled briefly in North Carolina before moving to the Winchester area -- his home base for the rest of his life.

He was an apple-orchardist neighbor of the late Sen. Byrd for more than 30 years. And when he retired, he noted in a statement:

"I tried to sevre Virginia, together with my colleagues, in containing the sound fiscal policies to which the state has been dedicated over the years."