By calculating the trapped particle fraction, solving the Grand\|Shafranov equation describing plasma equilibrium, and using Harris model, the magnitude and alignment of the bootstrap current in tokamak are calculated and analysed under the conventional shear regimes and also the negative central shear regimes. The conclustion we obtained are: through adjusting the profile parameters of plasma density, temperature and current, and the elongation k and triangularity d which describe the plasma shape, the alignment of bootstrap current profile with the equilibrium current profile can be produced...
