The volume pinning force, F p(max) , increases with increasing synthesis or sintering pressure (0.1 MPa–2 GPa) in materials prepared at high temperature (1050 °C) while it stays practically unchanged in those prepared at low temperature (800 °C). The position of F p(max) can be shifted to higher magnetic fields by: (1) increasing the manufacturing pressure or decreasing the temperature (2) additions (Ti, SiC, or C, for example), and (3) in-situ preparation. Grain boundary pinning (GBP) dominates in materials prepared at low temperatures (600–800 °C), while high-temperature preparation induces strong point pinning (PP) or mixed pinning (MP) leading to outstanding properties. In materials produced by spark plasma sintering (SPS), the position of F p(max) is higher than expected for both grain boundary and point pinning. The distribution of boron and oxygen in MgB 2 based material, which can changed by additions or the preparation conditions, significantly affects the type and strength of pining. Materials prepared under a pressure of 2 GPa with a nominal composition of Mg:7B or Mg:12B consist of 88.5 wt % MgB 12 , 2.5 wt % MgB 2 , 9 wt % MgO or 53 wt % MgB 12 , 31 wt % MgB 20 16 wt % MgO, respectively. Their magnetic shielding fractions at low temperatures are 10 % and 1.5 %, with a transition temperature, T c of 37.4–37.6 K. Although their magnetic critical current density at zero field and 20 K was 2–5×10 2  A/cm 2 , they were found to be insulating on the macroscopic level.