Gannett News Service said the Georgia Democrat whose 12th District represents part of the Augusta area, sent 35.7 million communications in 2009.
Gannett said those missives - such as mailings, phone calls, radio and print ads - cost $264,591, tops for Georgia's 13 House members.
In contrast, Republican Jack Kingston, Chatham County's other House member, spent $37,823 - 11th in the Georgia delegation.
The communications, monitored by a House committee that is supposed to weed out messages that are excessively self-promoting, are legal.
But in election years, they draw sharp criticism from challengers who consider them tax-subsidized campaigning.
This year, Barrow is drawing fire from Ray McKinney, one of four Republicans seeking the GOP nomination in Barrow's 12th Congressional District.
The Lyons resident called Barrow's spending "out of control and a waste of taxpayer dollars."
"Barrow," he added, "is famous around the country now ... but unfortunately for the wrong reason - excessive spending.
"Congressional approval ratings are the lowest they've ever been because people are sick and tired of ... unnecessary spending."
McKinney proposed slashing the costs of such communications by sending them only to people who request them.
Barrow spokeswoman Jane Brodsky did not dispute the accuracy of the Gannett compilation.
But Brodsky said communicating with constituents is a critical part of Barrow's job.
"He's in his district almost every weekend holding job fairs, health forums, veterans meetings, energy expos, town hall meetings and other events," she said.
"These announcements let people know about them. People come up and thank him."
Brodsky said she's not surprised he spent more than other Georgia congressmen.
"There are 22 counties in the district, and many communities have their own stations and newspapers. You can't reach everyone with just one of them."
She says the way the number of communications is calculated can be misleading.
For example, she said, an ad that runs four times in a 10,000-circulation newspaper must be reported as 40,000 communications.
She acknowledged that it seems "remarkable" that Barrow reported sending more than any other congressman.
But she said the House has a new reporting system and that she isn't sure how well it monitors reports for consistency.
Kyle Anderson, a spokesman for the House Administration Committee, did not return two phone calls made to seek comment.
University of Georgia political science professor Charles Bullock said sending such messages is a traditional perk of sitting members. And it's politically smart for Barrow to do so extensively, Bullock added.
"It's something incumbents do, and it's something constituents expect," he said.
Members have lost because voters thought they seldom heard from them, but not because voters heard too much from them, Bullock said.
Aside from providing useful information, he said, announcements get a congressman's name out.
"Year after year," he said, "you develop name familiarity even if people glance them and toss them. And people are more likely to vote for you than someone they never heard of."
In terms of money spent, Barrow did not make the top 10 nationally, Gannett said. No. 1 was Dina Titus, D-Nev., who shelled out $470,059.
In all, Gannett said, House members spent more than $45 million last year - up from $20 million in 2007.
McKinney lamented that trend.
"Communication with constituents is a necessary function," he said. "... But it shouldn't cost more than a quarter million dollars. We need to be smarter than that."