[en] A 78-year-old tree was harvested in 1988 ast 2.8 km east of the Nagasaki Pu-bomb hypocentre, where the local fallout of the 1945 blast was highest. Surface soil concentration of ^239+240Pu was 64.5 mBq g^-1 and that of ¹³⁷Cs was 87.4 mBq g^-1. The tree rings were analyzed for concentrations of ^239+240Pu, ¹³⁷Cs and ⁴⁰K. The concentration profiles over seven decades showed that the Pu was immobile, while Cs and K were mobile in the tree rings. In other words, the Pu concentration profile revealed a history of Pu in the surrounding environment of Nagasaki. However, the combined routes, via leaves from the atmospheric deposition and roots from surface soils to tree rings, made the record less clear. Surprisingly, the Pu from the Nagasaki Pu-bomb in the tree rings of 1946-44 played a minor role in the concentration profile compared to that from global fallout. (Author)