RESUMEN
<p><b>OBJECTIVE</b>To study the absorption, translocation and accumulation of N, P and K on Achyranthes bidentata.</p><p><b>METHOD</b>The contents of N, P and K were determined by mean of sulfuric acid-hydrogen peroxide assimilating method, vanadium-ammonium molybdate colorimetric method and flame photometric method, respectively.</p><p><b>RESULT</b>The contents of N, P and K in the plant were decreasing during the growth period. The absorption rates of the three nutrients by A. Bidentata showed double-peak curves in the whole growth period, maximum absorption rate appeared in the middle ten days of October. About 8.59 kg of N, 1.36 kg of P and 7.40 kg of K were needed to produce each 100 kg root.</p><p><b>CONCLUSION</b>The key nutrients absorption period is in the first ten days of September and in the middle ten days of October.</p>