Atlanta is counting more than bodies in its tug of war with crime.

Among the casualties are a politician's dreams of a Senate seat and a controversial street sign.

The dreams were those of Maynard Jackson, the city's first black mayor, who until a few weeks ago hoped to become Georgia's first black United States senator by defeating incumbent Democrat Herman E. Talmadge next year.

Atlanta homicides -- now over 200, compared with 143 for all of last year -- helped change the mayor's mind. "My city needs me, particularly now," Jackson said early this month as he announced his decision not to run.

Money was apparently no object. Jackson had in his camp Atlanta show business lawyer David Franklin, a money raiser for Sen. Edward M. Kennedy (D-Mass.) with access to the big bankrolls of black stars.

Political observers say the crime question has become too big a liability for Jackson to bear in rural Georgia, where Atlanta is suspect even in the best of times.

Jackson's departure left the field to Talmadge, populist Lt. Gov. Zell Miller and Dawson Mathis, a rural congressman. Atlanta Congressman Wyche Fowler Jr. has hired South Carolina political consultant Marvin Chernoff, best known for his role in Charles D. (Pug) ravenel's 1978 race against Sen. Strom Thurmond (R-S.C.). Fowler is expected to make up his mind about 1980 contest before the end of the year.

Another victim of Atlanta's continuing crime is a 96-foot-by-22-foot billboard. It is under contruction on top of a downtown tire store owned by a critic of the city's police policies.

When completed, it will bear a running count of the city's homicide total and a message: "Warning: You are now in the city of Atlanta where the police are underpaid, undermanned, underequipped. Use extreme caution while here."

The message has some basis in fact. Discrimination lawsuits dating back almost a decade have kept the city from hiring 200 additional police officers. Patrolmen with college degrees start at $12,933 a year. Only sergeants or officers of higher rank may routinely carry high-powered weapons.

Workmen arriving to put up the $9,000 sign on two mornings recently found their equipment vandalized and a truck containing sign panels gone.

The irony was not lost on the city dubed the "Murder Capital of the U.S." by an Atlanta daily in a front page headline.

The Atlanta Journal awarded the title in an article saying Atlanta led the nation's 30 largest cities with 26.2 homicides per 100,000 population during the first six months of this year. Washington, D.C., had 14 homicides per 100,000, the newspaper reported.

Public Safety Commissioner Lee Brown disputed the title, last bestowed on Atlanta in 1973 for 263 slayings that year.

Brown said the Journal's population figures were low. The newspaper said its figures came from the latest available Census Bureau data.

Meanwhile, the city looks for ways to ease citizen tension resulting from the highly visible killings of an Ohio physician on convention here in June and a legal secretary by a berserk Vietman veteran last month. The two deaths and the veteran's suicide all took place on downtown streets.

Superior Court Judge Charles L. Weltner, a liberal proposed "stop and frisk" searches by police, who would "sweep the streets once or twice a day" of firearms and other illegal weapons.

Old laws against public abuse should also be enforced, said Weltner, known for his 1966 decision to quit a reelection bid for Congress rather than support segregationist Lester Maddox, the Democratic nominee for governor.

In speeches to Atlanta civic clubs, Weltner has also urged searches at Hartsfield International Airport, whose 36 million passengers each year make it the world's second busiest. Drugs coming through the airport are a major factor in Atlanta's crime, Weltner said.

Some of the judge's proposals have worried civil libertarians. They could lead to police brutality, warned Gene Guerrero, executive director of the state's American Civil Liberites Union.

Meanwhile, the city administration has pushed for passage of tougher gun and ammunition laws, even if they conflict with looser state regulations.

The city has announced it will build six $4,100 police booths downtown and man them with 20 to 30 rookie officers around the clock, in an attempt to increase police availability and visibility.

The plan started an argument about whether criminals would now move without fear to boothless areas. A downtown business group, Central Atlanta Progress Inc., released a report showing only a small percentage of the city's crimes take place downtown.

To improve the city's image out of town, a coalition of Atlanta business about tourist groups is planning a $70,000 "Greater Atlanta Project" to assess national attitudes about the city.