The invention discloses a Method for generation of mask data. For N-style grid part, partly working out the first processing difference between the sizes of resists pattern size brought by photo-mask process and the manufacture size by dry encroachment process. Then, for P-style grid part, working out the second processing difference between the sizes of resists pattern size brought by photo-mask process and the manufacture size by dry encroachment process. Then, working out the differential value(DeltaLp)of the first processing difference and the second processing difference, utilizing the worked differential value to adjust the P-style grid part abstracted from design data. Then, utilizing the design data adjusted by this different value to exert light intensity emulation to produce mask data. Therefore, in the mask data of bigrid structure contained semi-conductor integrated circuit components, they can adjust and constitute dimensional difference caused by dry erosion in different conductivity grid parts in luminous intensity emulation. |