The objective of this paper is an analysis of some selected features of musculature and fatness of carcasses, and of the quality of meat of fatteners from mass population differentiated by meat contents in their carcass. The investigations were carried out using 146 porkers of mass stock. The investigated animals were selected on a random basis. The percentage content of meat in carcasses of all the animals under investigation was determined using an ultrasonic apparatus type Ultra-FOM 100. The following parameters were values were measured for the purpose of estimating the quality of meat: an acidification degree of the muscle tissue (pH₃₅, pH₁₂₀, pH₂₄), an electrical conductivity (EC₃₅ , EC₁₂₀ and EC₂₄), and an R1 (IMP/ATP) coefficient of energy changes; a colour of meat in an L*a*b* system, a WHC value, and a drip loss from the muscle tissue. The results obtained showed only slight tendencies towards the decrease in the quality of meat, and the increase in the meatiness of fatnesses, regardless of the carcass weight. Generally, the unfavourable changes were stated only in the colour of the meat investigated, and in the drip loss levels occurring in the muscle tissue.