WASHINGTON (AP) _ Black leaders charged Wednesday that the increase in discrimination complaints by federal employees reflects a biased attitude among supervisors who believe the enforcement system will not hold them accountable.

Members of Blacks in Government proposed possible changes in the system as the group began its ninth annual training conference at a Washington hotel. The non-profit organization also introduced a kit to educate employees about how to deal with discrimination.

''It is clear that the federal manager who discriminates does so in reliance on the fact that the enforcement system designed to hold him or her accountable does not work,'' said Oscar Eason, chairman of the group's board of directors. ''It is fatally flawed.''

Rubye S. Fields, national president of the group, said they have received ''an increasing volume of complaints from federal employees about discrimination in the workplace.'' She said the complaints ranged from disparate treatment in assignments to failure to promote, demotions, terminations and involuntary reassignments.

Eason cited the results of a 20-month study by the Washington Council of Lawyers, which found a backlog of discrimination complaints at federal agencies and conficts of interest as Equal Employment Opportunity workers process complaints against their own agency.

The House government operations subcommittee requested the study and released the data last month.

According to the study, the EEO's deadline of processing complaints within 180 days is rarely met. In fiscal 1985, the average processing time for a complaint at the Veterans' Administration was 1,100 days; at the Department of Agriculture, 1,105 days; at the Department of Health and Human Services, 771 days; and at the Postal Service, 443 days.

More than 18,000 federal employees file formal discrimination complaints each year.

The study ''shows clearly that victims of discrimination are being denied equal protection of the law,'' Eason said.

He suggested that President Reagan issue an executive order overhauling the enforcement system. Eason said the complaint process should be taken away from federal agencies and transferred it to a new agency.

The new agency would handle complaints from federal employees while the Equal Employment Opportunity Commission deals with private cases.

Eason also said the group would ask Congress to review federal agencies and their implementation of affirmative action programs, and authorize a study on the effect of discrimination on the workplace.

''We believe these steps are necessary to assure that this nation meets its obligation to assure equal opportunity and equal protection of the laws to all of its citizens,'' Eason said.

During its five-day conference, the group plans to train more than 100 chapter presidents on how to present its new kit of fact sheets and audiotapes.

The package, titled ''Winning Ways,'' contains fact sheets on documenting complaints, filing out a federal job application form and coping with discrimination in the workplace.

The latter fact sheet includes a step-by-step discription on how to file a complaint to the EEO.

Blacks in Government is a 12-year-old non-profit organization, which is dedicated to the socio-economic, professional and cultural development of black government workers. It is based in Washington and has more than 100 chapters representing federal, state and local government employees.