New organophosphoric acid ester anhydride derivatives, more particularly new thiopyrophosphoric acid P,P,P'-trialkylester-P'-dialkylamide of the formula ##STR1## wherein R.sub.1 is an alkyl group of 3 to 6 carbon atoms and R.sub.2, R.sub.3 and R.sub.4 may be the same or different from each other and each are an alkyl group of 1 to 6 carbon atoms are now provided. These new organophosphoric acid ester anhydride derivatives have high insecticidal, miticidal and nematocidal activities and are useful as an insecticidal, miticidal and nematocidal agent.