Digital holographic microscopy (DHM) enables 3D volumetric measurements of small objects with high magnification. DHM has been applied to measure a variety of experimental studies, including turbulent boundary layer, spray droplets, individual cells, development of zebrafish embryo, etc. In this study, a DHM system is applied to measure the morphology and locomotion of two groups of Caenorhabditis Elegans (C. Elegans) with different development conditions (ATGL-1 group and n2 group) in an 8-day time period from their hatching to the adult stage, whose body lengths range from hundreds of micrometers to one millimeter. The length and volume are determined to describe the morphology of the C. Elegans at different development stages. The locomotion of the C. Elegans is divided into linear motion and curl motion. The kinetic energy derived from the two types of motion describes the extent of how active the C. Elegans is. The statistics of morphology and locomotion of the two groups of C. Elegans are compared at different development stages to illustrate the influence of the applied development conditions.