Cornell M. Jones, a reputed "kingpin" of Hanover Place NW, the city's busiest and most brazen cocaine market, pleaded guilty yesterday to a charge of conspiracy to distribute cocaine.

Jones, who faces a maximum sentence of 30 years in prison and a fine of $250,000, smiled and waved to a group of family members and friends after he entered the guilty plea in U.S. District Court.

Judge Joyce Hens Green set sentencing for Jan. 8. Jones remained in jail without bond.

After Jones was arrested in an undercover "sting" operation on Oct. 29, police said they seized more than $2.5 million in cash, jewelry, cocaine, cars and gold from his house, two apartments, and two safe deposit boxes.

As part of the plea agreement, however, U.S. Attorney Joseph E. diGenova promised not to place any charges against Jones' mother, father, sister, and girlfriend in connection with his drug-dealing offenses.

"He's been one of the key kingpins among the drug dealers on Hanover Place and in the city," diGenova declared.

He described the block near the intersection of North Capitol Street and New York Avenue as "one of the major drug dealing centers of the Washington area" and said Jones' guilty plea was "a significant accomplishment in the continuing effort to clean up Hanover Place and the rest of the city. There's more to come."

According to Assistant U.S. Attorney E. Thomas Roberts, Jones was arrested in the Hyatt Regency Hotel on Capitol Hill after paying $30,000 in cash to D.C. police undercover officers for a one-kilogram package of a white powder that he believed to be cocaine.

In a statement filed earlier, Roberts said Jones told the undercover police that he would be able to "handle" 20 kilograms of cocaine a week.

In an unsuccessful motion to have Jones released on bond, his attorney, James W. Robertson, a professor at Howard University Law School, described Jones as a member of "a very close-knit family" who has "given so much to his community."

He said that Jones, 28, who grew up on Hanover Place and now lives at 6204 Guinevere Ct. in Glenn Dale, is a part owner of a service station and a construction company.

He said Jones has coached teams for the Metropolitan Police Boys Club, provided "gym fees for underprivileged kids" at the House of Champions, a boxing gym on Georgia Avenue NW, and contributed money to send three students to college.

Last week Robertson filed a petition signed by about 100 persons, including more than a dozen persons who live on Hanover Place, asking Green to release Jones on bond.

In a reply, Robertson and Assistant U.S. Attorney David S. Krakoff said Jones' businesses and charities were "nothing more than a way to pose a legitimate appearance for a man who makes literally millions of dollars in illegal drug trafficking." They said Jones heads a "drug network" that sells "hundreds of thousand of dollars of cocaine each week on Hanover Place."

According to court records, Jones was convicted here in 1980 of possessing narcotics with intent to distribute and of aiding and abetting in a bank robbery in Virginia in 1974.

Alvin V. Bailey, of Northeast Washington, who was arrested with Jones at the Hyatt Regency, is being held without bond on narcotics charges pending grand jury action.