"When I first saw her, I didn't think we looked alike at all," Fey told TV Guide in an interview released Tuesday.
"Then during the ( Republican Party) convention, I started to think, 'OK, maybe a little.' ... We glue my ears down. That's one of the tricks," Fey said.
Fey's lampooning of Palin in a series of sketches on "Saturday Night Live" have more than doubled ratings for the long-running late-night comedy show and have been seen by millions more in online replays.
The Alaska governor entered the U.S. national political stage when Republican presidential candidate John McCain picked her as his running mate in August.
Palin appeared as herself on the satirical show Saturday in a series of skits that played off her striking physical resemblance to Fey.
"Saturday Night Live" executive producer Lorne Michaels said Palin's aides asked for her to appear immediately after seeing Fey's first impersonation of her about a month ago.
Michaels told Entertainment Weekly that Palin had a powerful connection with people and could end up on television if the Republicans lost the November 4 election.
"I think she could have her own show," Michaels said. "I think Palin will continue to be underestimated for a while. I watched the way she connected with people, and she's powerful.
Fey, 38, the Emmy Award-winning star of the TV comedy "30 Rock" and the movie " Baby Mama," told TV Guide she did not feel she had totally nailed Palin.
"I expected people to be like, 'Ahhh, we thought it'd be better than that,'" she said, adding, "I stand by the pieces as both fair and quite gentle."
Interviewed while watching the October 2 debate between Palin and Democratic vice presidential candidate Joe Biden, Fey said: "I'll tell you, that lady is five times better looking than I am. She's 44? She's got none of that droopy s ... She's keeping it tight!"