The experiment was conducted at Jimma Agricultural Research Center during 2016 cropping season. With the objective of to determine the phenotypic and genotypic association and thereby comparing the direct and indirect effect of traits on grain yield of maize inbred lines. The highest phenotypic and genotypic coefficients of variation were observed for grain yield per hectare, thousand kernel weight, ear height, ear diameter, anthesis-silking interval, and plant aspect. Grain yield indicated positive and highly significant (p<0.01) genotypic association with ear diameter, number of kernels per row, days to 50% silking, number of kernel rows per ears, 1000-kernel weight and leaf width. At phenotypic level grain yield showed positive and highly significant (p<0.01) correlation with number of kernels per row and ear diameter. Path coefficient analysis at the genotypic level revealed that number of kernels per row, number of kernel rows per ears, plant height, days to maturity, 1000-kernel weight, leaf width and plant aspect had a positive direct effect on grain yield. Number of kernels per row, Number of kernel rows per ear, plant height and 1000-kernel weight exerted high direct effects and also indicated positive and strong association with grain yield. The traits which indicated direct effect and having positive association with grain yield can be used as reliable indicators in direct selection of grain yield improvement

Keywords: character association, inbred lines, morphological, path coefficient