London Marathon chief executive Nick Bitel said that there was "absolutely no chance" that this year's marathon would be cancelled, reports Xinhua.
At least three people were killed and 140 injured after the blasts at the finish line of the event in Boston Monday.
The London Metropolitan Police said a security plan was in place for London's race but "we will be reviewing this".
The BBC quoted the Met Police's Ch Supt Julia Pendry, the commander in charge of policing the London race, as saying: "A security plan is in place for the London Marathon. We will be reviewing our security arrangements in partnership with London Marathon."
British Prime Minister David Cameron said: "The scenes from Boston are shocking and horrific - my thoughts are with all those who have been affected."