Seawater samples were collected in the water column of the Canda Basin and the Bering Sea from aboard the R/B Xue Long during August 1999. Activity concentrations of dissolved and particulate 234Th were measured using beta countion techniques to quantify the scavenging and residence time of 234Th and organic carbon export fluxes. Prinary production (PP)and bacterial production were also determined in the study areas through in situ incubation experiments. Singificant 234Th scavenging was observed in the upper 100m of the water column in both study ares. with up to 40% of 234Th defictit found at Bering Sea stations and -15% of 234Th defictit at the Canada Basin station. Measured PP decreased from -12.5μmol C/m3/hin in surface water to near zero at -100m depth. with an integrated PP of 3.83mmol C/m2/d in the Canada Basin. Bacterial production. on the other hand. was on the order of 2.0mmol C/m2/d. which is up to 52% fo the integrated PP. Particulate organic carbon (POC) export fluxes derived from 234Th/238U disequilibrium were -1mmol C/m2/d in the Canda Basin and -10mmol C/m2/d in the Bering Sea. with fluxes in the latter areaheing 5 to 10 times higher than those found in the Caada Basin. These expon fluxes correspond to a ThE ratio (the ratio of 234Th-derived POC export to primary production) of 0.23 for the Canada Basin and 0.7 for the Bering Sea. The highe ThE rations in the study areas suggest a decoupling of production and particulate export in the high-latiude ocean. Rations fo POC to particlate 234Th (μmol C/dpm) decreased consistertly with incerasing depth, suggestion that organic carbon is preferentially remineralized relative to 234Th. Interestigly, The profile of particulate 234Th in the Canada Basin showed a unique characteristic: particulate 234Th activeites increased with increasing depth. suggesting a contiuous scavenging of 234Th and a rapid settling rate of the particles.