This paper studies the suitability of conductive knit fabric in order to produce a reliable breathing sensor. Conductive single jersey knit fabrics was manufactured from silver coated nylon yarn with different production parameters (stitch type (ST)- combination ratio (CR) and number of wales (NW)). A cyclic tester was built to simulate the breathing mechanism of a human being and to explore the influence of these parameters on the electric resistance. The results show that there is a significant effect on the resistance value by the difference in ST and CR, while the width of the sample doesn't show a significant effect.The best sample suited for breathing sensor is the one with increase in width (NW), less CR and normal stitch.