Twelve representatives from Cambridge's black community Wednesday night gave the City Council a list of 30 proposals aimed at improving race relations in the city.

James Washington Jr., a spokesman for the informal group, claimed there was "a strong possibility" of racial disturbance in Cambridge this summer if the proposals were not implemented. "None of us here wants to see that happen," he said.

The list of proposals included:

* Hiring more blacks as policemen, firemen, and other city workers, and giving promotions to those already employed by the city.

* Tightening up regulations against discrimination in housing and rentals

* Cleaning streets and sewers more often.

The Council expressed sympathy with the black demands and promised to act on them as soon as possible. Councillor Thomas H. D. Mahoney said he was impressed with the "reasonableness of the requests."

Immediate Action

"Some of the requests were for things which any city should do anyway," Councillor Barbara Ackermann said. She said she felt that some of the demands--such as those for more street cleaning and recreation--could be met immediately. Others, such as increased recruiting of blacks for city jobs, would take more time, she said.

The group of blacks will meet with the Council again next Thursday to see how much progress has been made on the proposals.