"We understand your desire to go home to Texas and spend more time with your family. But we hope you realize how necessary your continued service in the U.S. Senate is, for Texas and for our country," the letter stated.
While Hutchison's office confirmed receiving the letter, the senator didn't comment to the AP.
Hutchison lost the Republican primary race for governor earlier this month to Gov. Rick Perry, who now faces Democrat Bill White in the November general election.
In the middle of last year, Hutchison had said she would leave the Senate by the end of 2009 to concentrate on her race against Perry. She later said she would stay in the Senate longer -- until after the March primary -- to fight against the federal health care package pushed by President Barack Obama and congressional Democrats and also against Democratic proposals to limit carbon emissions.
"These issues are too important to leave the fight to a newly appointed freshman senator who will be selected in the midst of a political storm," Hutchison said in November. But she also said she was making it "crystal clear" that she would leave the Senate after the primary regardless of whether she or Perry won.
Recently, on the primary campaign trail in Texas, Hutchison indicated she would be leaving the Senate after the health care debate.
In their letter, the GOP congressional members cited Hutchison's accomplishments and noted that she is the only woman ever elected to represent Texas in the U.S. Senate.
"Kay, no one knows better than you the daunting complexity of the foreign and domestic challenges that our country faces," the letter said. "It is precisely because this is a historic period of profound decision and sweeping change that we feel obliged to say that the acuity of your vision and the breadth of your experience are needed more than ever."
Hutchison was elected to the Senate in 1993. Her current term runs through 2012.
Several Texas politicians from both major political parties have been waiting to run for Hutchison's seat when she leaves office.