In the present contribution we applied several statistical methods of time series analysis (Fourier transform, least-squares fitting etc.) to the time series of solar wind velocity data to search for hidden periodicities. The solar wind data wo analysed were obtained on probes at the distance 1 AU from the Sun and stretched over the 17 year interval from 1963 to 1980. Because of investigating
long-period components on time scales of 0.5 to 15 years in variations, we processed daily solar wind velocity values averaged over each Bartels rotation Nos. 1784 - 2006, i.e. 223 data. The analysis showed periods of 14.9-13-7, 7.2-7.1, 3.6-3.I, 2.8-2.6, 2.1- 2.0, 1.7-1.4, 1.3, 1.1, 1.0, 0.8, 0.7 and 0.6-0.5 years. Short preliminary comparison is given with periods found in various solar and geomagnetic indices.