We have fabricated high $T_c$ superconductor 20° twist grain boundary junction and measured its properties. For this $SrTiO_3$ substrate cut by 20° was prepared. $YBa_2Cu_3O_{7-x}$ also grew tilted by 20° on it. If YSZ was deposited on it a little, however, $YBa_2Cu_3O_{7-x}$ grew normal to the substrate on them. Therefore in case YSZ was deposited on a half of the substrate and $YBa_2Cu_3O_{7-x}$ grew on it, 20° twist grain boundary could be fabricated. YSZ was deposited by about 300Å and a half of it was removed by ion milling using a-MgO/a-CaO mask. X-ray diffraction studies revealed 20° twist grain boundary. The critical temperatures of about 86K were acquired on both sides. The current- voltage characteristics resembled RSJ type but Josephson effect was not found in magnetic flux dependence.