Abstarct: thermal conduction affairs can be devided into straight and reverse.in the straight affairs that are used more , geometry , border conditions , primary conditions , and also thermophysical qualities are obvious and the aim is calculation of heat distribution in the place using solving the equations.in the reverse affairs that are more paid attention and have many applications recently,a number of these datas in the border areas are unknown and the aim of solving the equations is their estimation using measured heat in the solving area.these kind of affairs are difficult in mathematics and sensitive to measuring faults intensely.total strategy in solving them is definition and minimizing an aim function that usually is chosen the sum of fault's squares using a repeating method. in this project,by means of coupled gradian method , thermal flux on the wall of sphere is estimated and experimental datas are simulated by adding fault to exact amounts (straight method).