Multiferroic materials (MF), in which ferromagnetism and ferroelectricity coexist, have attracted much attention in recent years. If the coupling between the magnetic and ferroelectric order is strong enough, MFs potentially allow the manipulation of electric and magnetic moments by magnetic and electric fields, respectively. Recently, we have synthesized multiferroic Ni1-xA1-xCr2O4 (A=Mn,Cu) to study the detail magnetic structure as a function of temperature (T) at low T by NPD. Initial measurements of T dependent XRD, dielectric & magnetization measurement have already done. In order to understand the origin of magnetoelectric MF behavior, it is necessary to understand the relation between its structural parameters and complex magnetic ordering. The structural studies as a function of T will provide microscopic level information of the origin of magnetoelectric coupling in these MFs.