Harry R. Hughes, who resigned as Maryland secretary of transportation to protest the handling of the billion-dollar Baltimore subway contract, announced today that he is running for governor.

Hughes said he will enter the 1978 Democratic primary "in a crusade to redeem our state from the morass of corruption into which it has sunk."

The 51-year-old lawyer is former majority leader of the Maryland state Senate and former chairman of the state Democratic Party. He was appointed by suspended Maryland Gov. Marvin Mandel in 1971 to head the massive transportation department - which oversees subway construction, the port of Baltimore, state highways, airports and mass transit.

He resigned last May 26 after a lengthy dispute with Mandel and other state official over the award of the contract for management of Baltimore subway construction. Hughes charged that the govenor had allowed Victor Frenkil, a wealthy Baltimore contractor and political contributor, to "taint" the contract award process by bringing pressure on state officials and on other contractors for a share of the contract.

By taking that action, hughes broke with Mandel and with Maryland's political traditions.

He joins a field of candidates that now included Acting Gov. Blair Lee III, altimore City Council President WalterS. Orlinsky, Baltimore County Executive Ted' Venetoulis, Attorney General Francis B. Burch, Maryland State Senate President Steny Hoyer, and Maryland Comptroller Louis Goldstein.

Hughers' campaign manager, Joseph M. Coale, said he has raised, about $50,000 so far to conduct the statewide campaign. Hughes said today he would conduct a grass-roots campaign clearly aimed at the state's image as a bastion of corruption.

"We will let the people decide who is tainted and who is not in this campaign," Hughes said at a press conference yesterday.

"Incredibly, just three weeks ago, Marvin Mandel (convicted on corruption charges in August) stated that corrpution should not be an issue in this campaign," Hughes said.

"In effect, Marylanders have been asked to put their blinders on again, to pretend that nothing really happened, to help sweep the past under the political rug. That we should be asked to do this is both appalling to me and certainly insulting to the electorate," he said.

"I've been in government for 22 years and Mandel had nothing to do with my election to the General Assembly," Hughes said. "Rather than Mandel doing me a favor in appointing me secretary of transportation, I can say I did him a favor in the way that department was run."

Hughes said there are some people he will not accept money from, but he will not discount support from people simply because they work for the current state administration.

He admitted he is a "dark horse candidate," but added that he "doesn't mind."