Characteristics are presented of the energy confinement time resulting from neutral hydrogen beam heating of JT-60 tokamak plasmas with a plasma current, Ip, of 1-2 MA, a line averaged electron density, e, of 1.5-7 × 1019 m−3 and an absorbed beam power, Pabs, up to 20 MW. The plasma energy content follows an offset linear relation to the absorbed power. The incremental energy confinement time for thermal components,,is almost independent of Ip and e at 60 ms, while the incremental energy confinement time for the total plasma energy,,decreases with plasma density. The value ofin JT-60 coincides with the prediction of the Shimomura-Odajima scaling of L-mode discharges.