D.C. Assistant Police Chief Ronal D. Cox, whose command includes the city's highly visible narcotics operation, is among five applicants recommended yesterday to Maryland Gov. William Donald Schaefer to run the troubled 1,545-member state police force.

State officials in Annapolis confirmed that Cox, 45, a 24-year veteran of the D.C. police department, was among five applicants recommended by a special search committee that has been combing through lists of potential superintendents in search of a successor for George Brosan, ousted by the Schaefer administration in the spring. Officials would not identify the other four contenders.

They said Schaefer has not indicated when he will nominate a candidate for the $59,800-a-year job. Schaefer's choice wouuld go to the Maryland Senate for confirmation.

Leaderless for four months and plagued by racial discrimination lawsuits, a training academy sex scandal, allegations of false academic credentials against its crime lab director and generally low morale, the state police force will present a formidable leadership task to its next superintendent, according to police officials and rank-and-file troopers in Maryland.

In an interview yesterday, Cox said he is up to the job. "It's a very interesting job, very challenging," he said. " . . . . It's an excellent department. It would be an honor."

In addition to internal problems in the Maryland State Police, several state legislators from the Washington area and other regions of the state are pressuring Schaefer to nominate someone to the police job who is not from Baltimore. This is a reflection of growing impatience with what they say has been Schaefer's record of appointing officials from his old mayoral administration in Baltimore and not spreading the political spoils more evenly around the state.

Bishop Robinson, secretary of the state's Department of Public Safety and Correctional Services, said the search committee interviewed at least 20 applicants for the state police job after it was advertised nationally.

While some applicants were from within the Maryland State Police, Robinson said, none was from the Baltimore city police.

"There were candidates from many parts of the nation . . . Oregon, the Midwest, California, Pennsylvania, Texas, Illinois," he said. The only local applicants were from the District and Baltimore County, he said.

Cox is one of four assistant chiefs in the D.C. police department in charge of inspectional services, which includes the department's intelligence and morals divisions. The narcotics enforcement operation comes under the morals division.