The objective of this phase of Toxicological research on Lethal Concentrations of Heavy Metals in Tissue of Earthworms is to improve both ecotoxicological test in a chemically defined medium and a procedure of bioavailability study in field. In this first period we worked on breeding stock of earthworms species Eisenia fetida andrei in decomposing manure heaps to increase them and make them grow. We also installed two chambers with thermostats fixed at 20 C to do toxicity tests and we choose chemical species of heavy metal contaminants. For field procedure, we improved a practical way to sample both earthworms and soil in very close connections, avoiding artifacts. For both field procedure and laboratory tests, we tried to standardize a method to dissolve earthworms in acids and to analyze the concentrations of heavy metals inside. We started to make a preliminary set of samples in calcareous soils. Analysis of them are in progress. For lab tests, we started the first part of the test preliminary test with the different contaminants cadmium, copper, arsenic, mercury in an artificial medium named Artisol. Keywords France.