Today’s growth of thermal insulators has gained speed. An important application of thermal insulators is to prevent heat loss and saving energy. Use of thes types of insulators and the role of fabrics in thermal insulators caused huge developments in textile engineering. Engineers could produce such isolator composites using wast types of fabrics inculding knitted fabrics.However, due to complexity in structure of knitted fabrics producing a fabric with proper thermal conductivity consumes so much time and energy. The main aim of this work is to evaluate thermal conductivity in warp knitted fabrics. Different parameters of warp knitted fabric such as CPC, WPC (courses per centimeter and wale per centimeter) and yarn material were considered and the heat transfer through the fabric was modeled in 3D using an automatic script in a finite element solver. Using fluid Dynamics in model to simulate the heat transfer is a unique technique which increases the calculation precision, and that’s because of entering realistic terms into the problem, it is done by using two separate solvers in small iterations in two parts of solid and fluid heat transferchanging fabric specific factors can make simulation of different types of warp knitted fabrics easy and costless. Therefore, we can achieve absolute properties and begin the production without any side cost. Having the factors of CPC, WPC (which describes the loop form) as well as modeling procedure with current Standards gives us data like Heat Flux, cold side and hot side Temperatures of fabric, thus we can determine the thermal conductivity of fabric. To veriy the simulation results warp knitted fabrics with structures of 1×1, 2×1 and 3×1 where tested using Hotplate device. The temperatures of the cold side were recorded using infrared temperature sensor and heat flux was acquired from corresponding sensor. The variation of the cold side temperature of the warp knitted fabrics versus time were provided experimentally and compared to the theoretical (simulation) curves. The results showd the difference between the experimental and the simulation curves is high in transient state. However, insteady state, acceptable agreement was observed between experimental and simulation results. The error between simulation and test was about five percent. Key words Thermal Conductivity, Thermal Conductivity Coefficient, Single guid barWarp Knitted fabrics, Finite Element Metho