Pyrazoles, a class of five-membered nitrogen-containing heterocyclic compounds, showed antibacterial, anticancer and antioxidative activity, and so on. They also served as important intermediates in organic synthesis. To develop the general and straightforward methods to their synthesis is of great significance. In this paper, a series of tetra-substituted pyrazoles were synthesized from aldehydes, hydrazines and fumarate esters by three-component[3+2] cycloaddition reaction in the presence of chloroamine-T with 60%~87% yields. Their structures were confirmed by 1H NMR, 13C NMR, IR and HRMS analysis.