Na tripolyphosphate (1) was produced by one-stage conversion of 3 various oract. H(3)PO(4) and H(3)PO(4) with Na(2)CO(3) at 150-600 degrees C for 2 h. The P(2)O(5), content in I increased up to 61,72% with increasing calcination temp. and purity of the raw material. The phase compn. of I was studied by X-ray diffraction anal.