D.C. School Superintendent Floretta D. McKenzie will ask the Board of Education to abandon the school system's "no-expulsion" rule and permit students to be expelled from school for distributing drugs or carrying dangerous weapons, a school spokeswoman said yesterday.

The proposed change, according to spokeswoman Janis Cromer, was sparked by two incidents in the last two weeks in which students were found carrying guns. Two students were shot in Northeast's Spingarn High School gymnasium Oct. 21 during an argument over a radio, and a seventh grader at Jefferson Junior High School in Southwest Washington was arrested Friday after school officials confiscated a loaded .38-caliber handgun from his book bag.

"Certainly, the two incidents in a matter of weeks have caused a lot of concern," Cromer said. "We want to send a message out clearly that we want our schools to be drug-free and weapon-free. Having an expulsion option would help us to reinforce that message."

The District is the only metropolitan area jurisdiction that does not allow expulsions for any reason. Under the existing disciplinary policy, Cromer said, a student found to be carrying a deadly weapon or distributing drugs is automatically placed on "major suspension" for up to 10 school days. In addition, she said, "we work very closely with the criminal authorities to bring charges against that person."

Cromer said McKenzie has already discussed changing the policy with several school board members, including President R. David Hall, and is to meet this week or next with board members, the school system's lawyer and the director of security.

The school board would have to approve any change in the no-expulsion rule.

Permitting students to be expelled from schools would signal a shift in the District's approach to disciplinary problems. "Part of the philosophy behind why we have had 'no-expulsion' is that what has happened is that the student gets expelled and maybe the schools themselves have alleviated one problem, but you don't do anything on behalf of that student," Cromer said.

Because many students who are kicked out of one school system end up enrolling in a neighboring jurisdiction's schools, she said, "Our feeling is that expulsion may just be giving another jurisdiction the problem."

Cromer said expulsion has not been a major issue previously because "it was so rare that we had . . . cases" that might warrant it. In the four years before the recent incidents, she said, only one student was found carrying a gun. Six students were found with knives last year.

George H. Margolies, legal counsel to the D.C. school system, said he had been researching whether the District's compulsory education law would require school officials to provide alternative means of education for students expelled from school.

He said the District has had the no-expulsion policy since at least 1977, when the disciplinary code was revised. While the emphasis then was on protecting the rights of disciplined students, he said, "Obviously there's a different atmosphere now in which rights of other youngsters going to school have to be balanced."

Ruth Harris, president of the D.C. Congress of Parents and Teachers, expressed support for the change. "That sounds like it would be justified," she said. "I would think it would be very difficult to maintain the school system if you had people that you knew were selling drugs or committing other offenses on your grounds," she said.

Washington Teachers' Union President Harold Fisher Jr. also applauded the proposal. "We would definitely back it," he said. "It's very difficult to carry on a viable instructional program when you have to deal constantly with children who are disruptive."

Cromer said McKenzie supports permitting expulsion under certain circumstance, but not making it mandatory. Prince George's County adopted a policy in 1982 requiring expulsion of students found to be carrying weapons or distributing drugs.

During the 1984-85 school year, 196 students were expelled, 143 for carrying weapons, according to spokesman Brian J. Porter. "It is very clear to us that the only way to ensure a safe, positive environment is to remove those students whose behavior threatens or endangers the safety and welfare of our students and faculty," Porter said.

Last school year, Fairfax County expelled five students, all for selling or distributing drugs, and Montgomery County expelled three students. No student was kicked out of public schools in Arlington County or Alexandria.