Presidential candidate John Glenn hopes to use an Aug. 29 fundraiser in Maryland to show that he is chipping away at the seemingly monolithic support for former vice president Walter F. Mondale among the state's Democratic leaders.

Baltimore County Executive Donald P. Hutchinson, who is heading the Glenn effort in Maryland, said the Ohio senator will use the event at the Martin's West catering hall to announce the names of a dozen or so elected officials from across the state who have agreed to support or coordinate his presidential campaign in Maryland.

Among that group will be several state legislators with strong district support, including Sen. Sidney Kramer (D-Montgomery), Del. Clayton Mitchell (D-Eastern Shore) and Sen. Michael J. Wagner (D-Anne Arundel), state party sources said. First District Congressman Roy P. Dyson is also expected to endorse Glenn, the first among Maryland's seven House Democrats to do so.

In addition, a substantial number of Prince George's legislators and county officials have indicated they will support Glenn. But official announcement of their allegiance has been held off in part because the county's congressman, Steny Hoyer, has told associates he prefers Glenn but is concerned that an endorsement would run counter to the sentiment in his increasingly minority and labor-dominated district. Prince George's County Executive Parris N. Glendening, who officially said he is undecided about the candidates, privately supports Glenn, associates said.

Five months ago, Mondale came to Maryland for a similar event at Martin's West and lined up several key state officials, including Gov. Harry Hughes, Lt. Gov. J. Joseph Curran Jr. and Comptroller Louis L. Goldstein. Earlier, Mondale had won the endorsements of Attorney General Stephen H. Sachs, U.S. Sen. Paul S. Sarbanes and representatives Michael Barnes and Barbara Mikulski.

Mondale will put in another Maryland appearance next month and has sent letters to all Democratic officials requesting support.

Hutchinson said yesterday that "they Mondale's supporters have most of the statewide identifiable names, but we don't see any grass-roots organizing taking place at all for Mondale."

A spokesman in Sarbanes' office, which is helping run Mondale's Maryland effort, said, "Obviously Sen. Glenn is going to have support in various parts of the state, but it seems to me that the most successful officials are with the former vice president."

One top party official said yesterday that some Maryland Democrats who committed earlier to Mondale are considering changing to Glenn in part because he is viewed as the most electable Democrat and in part because of Mondale's increasing association with various special-interest political groups, including labor unions.

A poll completed this summer by Potomac Survey Research, a Bethesda polling firm, showed Mondale narrowly beating Glenn among Democratic voters statewide. But Glenn easily was preferred in Montgomery County and tied Mondale in Prince George's.

Lanny Davis, the pollster and a Maryland member of the Democratic National Committee, said yesterday the results were surprising because the state's Democrats have frequently supported the most liberal candidate, and Mondale is generally perceived to be more liberal than Glenn.