Abstract: A resin composition for agricultural film, which composition contains 100 parts by mass of a synthetic resin (A) and the below-specified amount of a polymer stabilizer (B). Polymer stabilizer (B): an adduct obtained by adding a compound (b1) represented by the following formula (I) to a polymer (b2) having a molecular weight of at least 300: (wherein n represents an integer of 1-4; X represents —O— or —NH—; and R represents a hydrogen atom, a C1-C20 aliphatic acyl group, a C1-C20 aliphatic polyacyl group, a C1-C20 aromatic acyl group, or a C1-C20 aromatic polyacyl group). Amount of polymer stabilizer (B): such an amount that makes the amount of nitrogen atoms contained in the polymer stabilizer (B) 0.0005-1 part by mass.

Abstract: A stabilized synthetic resin composition obtained by adding (1) 0.01 to 5 parts by weight of at least one monopiperidine compound represented by the following general formula (I): ##STR1## wherein R.sub.1 represents an alkyl group, an oxyl group or an acyl group, andR.sub.2 represents an aliphatic monoacyl group carrying 12 to 30 carbon atoms,and (2) 0.001 to 5 parts by weight of at least one polypiperidine compound having two or more tetramethylpiperidine groups represented by the following general formula (II) per molecule: ##STR2## to 100 parts by weight of a synthetic resin.