A pot experiment was carried out using brown earth collected from local farmland to study effects of soil bulk density on photosynthesis of maize (photosynthesis rate, stomatal conductance, intercellular carbon dioxide concentration) and chlorophyll(a,b), and their regulation through application of organic manure and tillage. Results show that between treatments different in bulk density little difference was observed in chlorophyll concentration in leaves of maize before its jointing stage, but much was afterwards (p＜0.01), continuous increase in chlorophyll concentration was found during the growth stages under study; photosynthesis rate was negatively related to soil bulk density and intercellular carbon dioxide concentration, but positively to stomatal conductance; in soils high in bulk density, application of organic manure to raise soil organic matter up to 40～50 g kg^-1 showed an ideal regulatory effect, while in soils low in bulk density, the effect of soil organic matter in the set range of the study was always significant. Soil organic matter around 15 g kg^-1 restricted the growth of maize, and should be raised at least to 3% or more; tillage improved physiological indices of the maize, however, depth of the tillage had little significant effect on chlorophyll and photosynthesis indexes; when the tillage reached 30～40 cm in depth, its effects on various indices peaked and any further increase in tillage depth did not improve the effectcor.