We investigated superhump evolution, analysing optical photometric observations of the 2000 February-March, the 2002 October-November, and the 2006 September superoutbursts of SW UMa. The superhumps evolved in the same way after their appearance during the 2000 and 2002 superoutbursts, and probably during the 2006 one. This indicates that superhump evolution may be governed by invariable binary parameters. We detected a periodicity in the light curve after the end of the 2000 superoutburst without any phase shift, which seems to be the remains of the superhumps. We found QPOs at the end stage of the 2000 and 2002 superoutbursts, but failed to find extraordinarily large-amplitude QPOs, called 'super-QPOs', which previously had been observed in SW UMa.