First impressions will be important when Gen. David H. Petraeus moves into the CIA’s Langley headquarters as the fourth CIA director in the past seven years.

The agency staff is always nervous with change, particularly when the new director comes with a high-profile military background, a history of regularly changing jobs and a hint that this may just be a temporary stopover on the way to something else.

Senior CIA officials, who lived through the unsuccessful, brief tenures of John M. Deutch in the mid-1990s and Porter J. Goss a decade later, talk about both of them arriving with their own entourages and agendas to shake things up.

Leon Panetta, the current director, heeded advice he had gotten and arrived with only one person, Jeremy Bash, a lawyer who had worked as a staff member of the House Permanent Select Committee on Intelligence. Recalling that, one former senior CIA official said Wednesday, “Petraeus should get out of the car with only one military aide.”

Robert L. Grenier, a retired longtime CIA officer, recalled that Deutch came in 1995 from the Pentagon, where he had been deputy defense secretary, but with the expectation that after a year he would return as defense secretary. “Petraeus,” Grenier said, “would be making a big mistake if he did what John Deutch did, being obvious [by bringing in] uniformed persons everywhere on the seventh floor.”

Goss, who had chaired the House intelligence panel, arrived with an agenda from the second Bush White House to cut out agency “opponents” of policy. In his first weeks in office, the former congressman tried to hire a former CIA officer whose separation from the agency took place under a cloud. When word was leaked to the news media, Goss’s staff attempted to find the leaker — which led to confrontations with top clandestine operatives, who subsequently resigned.

Michael V. Hayden, an Air Force general who became the CIA’s director in 2006, thinks that Petraeus will see many things at the agency that will be familiar.

“He will find, like I did, that the CIA is the most militarized civilian organization, with all the values you find in the services,” Hayden said. Most agency employees are hardworking, devoted to what they are doing. and loyal to the country and the agency, he added.

As for advice, Hayden said that Petraeus will succeed if he does the things that made him successful as a company commander. “Eat with the troops, walk around and talk to them, and, by all means, protect them.” But, he added, Petraeus will also find that at the agency, “they don’t do hierarchy at all. Some called me ‘general,’ some ‘sir,’ but many called me ‘Mike.’ ’’

John Gannon, a veteran analyst and onetime CIA deputy director for intelligence, said: “It’s not where [CIA directors] came from; it’s what they did when they got to the agency.” He said that although integration of intelligence and the military in Iraq and Afghanistan today flourishes in part thanks to Petraeus, he wished that “the agency got back to being known for stealing secrets and not drone warfare.”

Along with several other former agency officials, Gannon pointed out that Gen. Walter Bedell Smith, who ran the CIA from 1950 to 1953 and had an enormous impact on its future, “understood it was a civilian organization whose major responsibility was to the president, civilian agencies and Congress,” with success having “a lot to do with his relationship with the president.”

John McLaughlin, who was deputy CIA director from 2000 to 2004 and for several months the CIA’s acting director, said he thinks the agency will be enamored with Petraeus, as long as he defends the personnel there and shows respect for their work.

McLaughlin described as “myth” that CIA employees recoil from military outsiders. The “CIA is so integrated with the military in so many fields,” he said. “Since 9/11 there is a comfort level that didn’t exist before.”

But he pointed out that Petraeus will learn that, compared with the Defense Department, “the CIA is relatively small, the focus is on individuals and instead of an extensive chain of command [as in the military], the organization has a relatively flat structure.”

Petraeus comes to the agency with a particularly high profile and, like George H.W. Bush before him, has long been seen as having presidential aspirations. Bush had to sign a letter agreeing not to run in 1976 as part of his confirmation. That profile is seen within the agency as both a plus and a minus, veterans say.

“The challenge for Petraeus is to avoid promoting himself rather than the organization,” said Gannon.

He cited as an example John McCone, the Republican businessman who became CIA director in the Kennedy administration. “McCone was hugely influential inside the White House and high government circles,” Gannon said. “He was not on ‘Meet the Press,’ nor did he become a familiar, public figure.”