Intracellular Cd[2+], Na[+] and K[+] contents were determined with Cd[2+] -treated and -untreated cells of Pseudomonas sp. No. 40. The K[+] content of the cells grown in 3M NaCl SGC medium (Sehgal and Gibbons complex medium) with 1,500ppm or 2,000ppm CdCl[2] was almost the same as that of the cells cultivated in 3M NaCl SGC medium without CdCl[2], whereas remarkable decrease of K[+] content was found in the cells grown in 1M NaCl SGC medium with 500ppm or 1,500ppm CdCl[2]. The same results were obtained with the untreated cells suspended in 1M or 3M NaCl SGC medium with 1,500ppm CdCl[2] with 60 min incubation. Viabilities of the cells were remarkably decreased by Cd[2+] in 1M NaCl buffer. However, they recovered their viabilities with the addition of Na-glutamate to the buffer as an energy source. Consequently, the physiological adaptation of strain No.40 to Cd[2+] was also found in 1M NaCl buffer, in the presence of Na-glutamate.