The synthesis of twenty methyldicyclohexyltin aromatoxyacetates from bis(methyl-dicyclohexyltin) oxide and aromatoxyacetic acids is reported. Their characterization by IR, NMR (^1H, ^1^3C, ^1^1^9Sn) is described. These compounds are five coordinate, carboxylate-bridged polymers except the compounds 11 and 12. A good linear relationship is found between the ^1^1^9Sn chemical shifts and the aryl groups. δ^1^1^9Sn=6.23σ+94.67, r=0.943 The results of the preliminary biossay showed that the compounds have b etter antibiotic activities to plant pathagenic fungi, herbicidal and inhibitory activities, especially high acaricidal activity.

Key words: BIOLOGICAL ACTIVITY, INFRARED SPECTROPHOTOMETRY, NMR SPECTROMETRY, C13 NMR SPECTROMETRY, PROTON MAGNETIC RESONANCE SPECTROMETRY, BACTERICIDAL AGENTS, HIGHPOLYMER, HERBICIDES, ORGANO TIN COMPOUNDS, PHENOXYACETIC ACID P