The work reported here consisted of an investigation of the influence of the profile of the spinneret channel in terms of Z/d, i.e. the ratio of the length I of the cylindrical part of the channel to its diameter d, on the process stability of viscose rayon spinning. Earlier experiments /7/ showed that the jet swell at the capillary outlet, which is the result mainly of the development of internal normal stresses P11 (axial) and P22 (radial), responds to an increase in Z/d. With Z/d = 0.5, for example, the ratio of the radii of the jet and channel Rj/R c = 1.8 - 2.2 while with Z/d = 3 it decreases to 1.4 - 1.6 and with Z/d = 5 reaches-its minimum of 1.15 - 1.2 after which it remains constant. Having regard to the relaxation of the normal stresses, the solution in the channel attains its ultimate steady-state flow conditions only with Z/d = 3 - 5. A higher ratio Z/d, moreover, gives a stronger jet. $ince the stress P11 determines the magnitude of the axia! toughening force, the geometric dimensions of the spinneret holes area significant factor in the stability of the spinning process and influence the strength of the fiber both in melt-spinning /8,pp.121;9/ and in spinning from polymer solutions /1,10/. ~he profile of the spinneret hole is characterized by the angle a of the iulet cone which [s a factor in the elastic turbulence /8 ,11/, and by index Z/d which governs the jet swell and the strength of the filament jet /I/. The influence of index Z/d was investigated in viscose rayon sp[nning by the centrifugal method. Spinnerets with a small index Z/d were found to give a large jet swell. Rayon spinning proceeds at a high jet stretch and a relativelylow speed so that in this case the jets undergo contraction and overstressing, the result being that they acquire nap and latent defects.