The 37-year-old Democratic member of the Maryland House of Delegates will seek the suburban Washington seat held by Republican moderate Constance Morella.
Shriver is the son of former Peace Corps director Sargent Shriver and Eunice Kennedy Shriver, founder of the Special Olympics and sister of President John F. Kennedy. He is also a cousin of Maryland Lt. Gov. Kathleen Kennedy Townsend.
Shriver said he has helped lead the fight for child care and early childhood education during his during his seven years as a state delegate.
"Now, those critical investments are under attack in Washington by a Republican administration and congressional leadership that has dropped all pretense of compassion from their conservatism," he said.
The Democratic primary for the seat will be held in September, 2002, and the general election will be in November, 2002.