Alan Khazei, the nonprofit leader who is hoping to succeed Edward M. Kennedy as a Democratic senator from Massachusetts, is highlighting his national-service work in two new advertisements.

Both spots, one produced for television and the other for the Internet, applaud his work building City Year, the youth service corps, and fighting for the Edward M. Kennedy Serve America Act, a bill signed into law last April that will expand the country’s national-service programs.

“He led a movement to help craft and pass national legislation all from his office as citizen,” says the Internet ad. “Imagine what he could do in the Senate.”

“I’ve always believed one person has the power to change things,” Mr. Khazei says in the television commercial. “So I started City Year and we created 15,000 jobs teaching kids, rebuilding communities.”

Mr. Khazei took a leave of absence from his post heading Be the Change, a civic-engagement nonprofit group in Boston, to run in the Democratic primary on December 8 for the seat that was vacated when Senator Kennedy died. Be the Change manages ServiceNation, a coalition of groups that promote volunteerism and national service.

The Internet ad also plays with Mr. Khazei’s name: “Daisy? No, Khazei.” “Hazy? No, Khazei.” “Jay-Z? No, Khazei.”

The television ad:

The Internet ad: