The pedigree data of Czech Large White (ČBU), Czech Landrace (ČL), Czech Large White-sire line (BO) breed were used for calculation of trends in effective population size. Animals with known sex and born within 1980-2013 were analyzed. Animals born within 2011-2013 were assumed as the reference population. The effective population size was computed by different methods. The effective population size varied from 97 (Ne-AFp) to 704 (Ne-ln), from 72 (Ne-Coan) to 190 (Ne-Ecg) and from 35 (Ne-ln) to 103 (Ne-Ecg) for ČL, ČBU and BO in 2013, respectively. The method Ne-AFp, based on difference in increase of inbreeding between offsprings and their direct ancestors, were shown as the most optimal for Czech Republic conditions mainly due to their robustness (relative low differences between consequent years), completeness of pedigree and their flexibility (changes in animal numbers within generations).