With internationally common-used Glycine max (the salt-tolerant Lee68) and Glycine soja (the salt-sensitive N23232) as reference, this paper studied the polyamines (PAs) contents and polyamine oxidase (PAO) activities in the highly salt-tolerant BB52 (Glycine soja) seedlings, which showed that under 150mmol x L(-1) NaCl stress for 2d, the decrease of Put and Spd contents was more significant, but that of Spd content was less significant in roots of BB52 than in those of Lee68 and N23232. For leaves, the decrease of Put and increase of Spd contents were markedly observed in BB52. The ascent of (Spm + Spd)/Put ratios and descent of Put/PAs ratios showed a positive relation to their salt tolerance. The PAO activity in roots and leaves was all increased, and most obvious in N23232. The relationship between PAs levels in BB52 and its salt tolerance was also discussed.