  The Kerr solution is considered as a soliton-like background for spinning
elementary particles. Two stringy structures may be found in the Kerr geometry,
one string is real and another one is complex. The main attention in this paper
is paid to the complex string, which is connected with the Lind-Newman
representation of the Kerr metric source as an object with a complex
world-line. In a separate note, one new result is announced concerning the real
string: in the dilaton-axion gravity the Kerr singular ring may be considered
as a heterotic string, the field near the Kerr singularity coincides with the
solution obtained by Sen for heterotic string.
