Pesticides is a common name of one kind of drug that can kill insect, sterilize and kill harmful animals(or weeds) for protecting and enhancing the growth of the plants and corps. It particularly refers to medicine for preventing pests, regulating plants growth and weeding in agriculture. Pesticides can be chemical, biological(such as viruses or bacteria), fungicide, anti-infective agents, or any means to fight pests.

Pesticide categories:Classified by raw material sources, pesticides mainly divided into organic chemicals, inorganic chemicals, plant pesticides, and microbial pesticides.

Classified by the processing agent, pesticides can be divided into powder, wettable powder, soluble powder, cream, butter, concentrated emulsion, cream, paste, gel agent, smoke agent, fumigants, smoke agent, oil agent, granulation and particles, etc.

Classified by the control object, pesticides can be divided into insecticides, fungicides,acaricides, nematicides, rodenticide, herbicides,defoliants etc..

Agrochemical， currently common named in English pesticide ---- that is ‘killing medicament’.

Generalized agrochemical is defined material or several materials compound or preparations produced by chemical reaction, from biont or natural material, or biological production, in order to prevent, kill or control disease, pest, grass, or other harmful bionts, and to modify ,control, affect plant and harmful biont’s biological metabolism, growing, development and reproduction. Narrowed agrochemical is the chemicals applied in agricultural production in order to kill pests, funguses, harmful animals or ruderals and ensure and accelerate plant and crops growing. Specifically refers to the medicament of preventing pesticide, adjusting plant growing and killing ruderals in agriculture.

Agrochemical is divided into organic, inorganic, vegetative and mircoorganic types, and entomic hormone. It can be divided into powder, wettable powder, soluble powder, emulsion, mossible oil, emulsifiable concentration, emulsifiable paste, paste, colloid, fumigant, fumigant agent, smoke agent, oiling agent, granula, fine granule according to chemical form. Most of them are liquid or solid, few are gas type.

The chemicals are made into different types according to pest or disease and physical properties of the chemical, eg. powder mop spreading, water solution, suspension concentration and emulsion injecting, also into steam or gas.