The near-wake and flow interference around a row of five circular cylinders, staggered wavy cylinders and non-staggered wavy cylinders are investigated experimentally by using PIV and LIF techniques. The effects and characteristics of employing wavy cylinders instead of circular cylinders are discussed. The cylinders were arranged at T/d=1.5 with Re ranging from 125 to 40000. Results showed the staggered wavy cylinders give rise to a more stable flow pattern with less fluctuation and longer wake vortex closure length.