High yield and early maturity are important characters in corn breeding. The objectives of the study were to evaluate the responses to four cycles created by modified mass selection method to increase yield and early maturity of a purple waxy and to investigate the correlations between yield and among other important traits in a purple waxy corn (Zea mays L. var. ceratina) population. Four cycles was evaluated for two seasons in 2012/13. A randomized complete block design with four replications was used. The results indicated that the selection method has led to improvement in many characters of this population. C4 cycle gave the highest whole ear yield of 16.0 t ha-1 followed by 15.4 t ha-1 of C3 cycle. Although C4 also had the highest marketable husked yield (9.9 t ha-1 ), it had the lowest days to tasseling and days silking. Genetic gains per cycle were 0.68 (P≤0.01) and 0.37 (P≤0.01) for whole ear yield and marketable husked yield, respectively, whereas genetic gain for days to tasseling and silking was -1.8 for both traits. As correlations between marketable husked yield with days to silking and days to tasseling were negative and low, direct selection for marketable husked yield would result in early maturity in this corn population, and several generations of recurrent selection are required.