A room temperature-curable organopolysiloxane composition comprising: (A) an alkoxysilyl-ethylene group-terminated organopolysiloxane having, at each of terminals of a molecular chain, a group represented by the following structural formula wherein R 1 represents an alkyl group that has 1 to 20 carbon atoms and may have one or more substituent groups, and said alkyl group having not less than 3 carbon atoms may be a cycloalkyl group as a cyclic group; R 2 represents a hydrocarbon group that has 1 to 20 carbon atoms and may have one or more substituent groups; a represents an integer of 1 to 3; and n represents an integer of 0 to 10, wherein said component (A) is at least one alkoxysilyl-ethylene group-terminated organopolysiloxane selected from an organopolysiloxane represented by the following general formula (A) and an organopolysiloxane represented by the following general formula (B): wherein R 1 represents an alkyl group that has 1 to 20 carbon atoms and may have one or more substituent groups, and said alkyl group having not less than 3 carbon atoms may be a cycloalkyl group; R 2 represents a monovalent hydrocarbon group that has 1 to 20 carbon atoms and may have one or more substituent groups; a represents an integer of 1 to 3; n represents an integer of 0 to 10; 1 represents an integer of 0 to 10, and m represents an integer of 40 to 1,500; (B) an organopolysiloxane in an amount of 10 to 250 parts by mass with respect to 100 parts by mass of said component (A), and represented by the following general formula wherein R 2 represents a hydrocarbon group that has 1 to 20 carbon atoms and may have one or more substituent groups; and m represents a number at which the organopolysiloxane exhibits a viscosity of 10 to 1,000,000 mPa·s at 25°C; and (C) a curing catalyst in an amount of 0.001 to 20 parts by mass with respect to 100 parts by mass of said component (A). (A) an alkoxysilyl-ethylene group-terminated organopolysiloxane having, at each of terminals of a molecular chain, a group represented by the following structural formula wherein R 1 represents an alkyl group that has 1 to 20 carbon atoms and may have one or more substituent groups, and said alkyl group having not less than 3 carbon atoms may be a cycloalkyl group as a cyclic group; R 2 represents a hydrocarbon group that has 1 to 20 carbon atoms and may have one or more substituent groups; a represents an integer of 1 to 3; and n represents an integer of 0 to 10, wherein said component (A) is at least one alkoxysilyl-ethylene group-terminated organopolysiloxane selected from an organopolysiloxane represented by the following general formula (A) and an organopolysiloxane represented by the following general formula (B): wherein R 1 represents an alkyl group that has 1 to 20 carbon atoms and may have one or more substituent groups, and said alkyl group having not less than 3 carbon atoms may be a cycloalkyl group; R 2 represents a monovalent hydrocarbon group that has 1 to 20 carbon atoms and may have one or more substituent groups; a represents an integer of 1 to 3; n represents an integer of 0 to 10; 1 represents an integer of 0 to 10, and m represents an integer of 40 to 1,500; (B) an organopolysiloxane in an amount of 10 to 250 parts by mass with respect to 100 parts by mass of said component (A), and represented by the following general formula wherein R 2 represents a hydrocarbon group that has 1 to 20 carbon atoms and may have one or more substituent groups; and m represents a number at which the organopolysiloxane exhibits a viscosity of 10 to 1,000,000 mPa·s at 25°C; and (C) a curing catalyst in an amount of 0.001 to 20 parts by mass with respect to 100 parts by mass of said component (A). <EOS>