Smart textiles are fibrous structures that react to the environmental conditions. Today, these textiles are commonly used in military, medical, sports and environmental applications. This study undertakes to develop textile-based weft knitted strain sensors using knitting techniques, in order to be used to evaluate or measure human body movements and medical fields. In order to produce knitted strain sensors, three types of conductive yarns containing 28%, 40% and 80% stainless-steel fibers, were used to fabricate three different interlock structures on a double-jersey knitting machine with two different stitch densities. Using three different knitted interlock structure, the effect of knit, miss and tuck loops as well as knit density on the electromechanical properties of the knitted sensor will be investigated. The electromechanical properties of the produced strain sensors were measured using a Zwik tensile tester as well as pre-programmed microprocessor and the output data were recorded by CODE VISION AVR software. The Taguchi experimental design was used to analyze the data. The findings demonstrated that the effect of parameters conductive yarn type and fabric structure on the electrical sensitivity of the produced strain sensors is statistically significant but the parameter knit density has not significant effect. The results showed knitted structures containing higher strain-steel fiber percent present higher electrical sensivity as well as more efficiency. On the other hand, knitted structures containing tuck stitches possess highest electrical sensitivity in comparison to the knitted structures containing miss and knit stitches. Also, the results showed that the knitted strain sensors have good repeatability during cyclic tensile loading.