A process for producing an optically active cyclopropane compound represented by the formula (4): ##STR00001## wherein R.sup.3, R.sup.4, R.sup.5 and R.sup.6 are the same or different, and represent a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group, and so on; and R.sup.7 represents a C1-6 alkyl group; and * represents an asymmetric carbon atom, which comprises reacting a prochiral olefin represented by the formula (2): ##STR00002## wherein R.sup.3, R.sup.4, R.sup.5, and R.sup.6 are as described above, with a diazoacetic acid ester represented by the formula (3): N.sub.2CHCO.sub.2R.sup.7 (3) wherein R.sup.7 is as defined above, in the presence of an asymmetric copper complex prepared from an optically active cycloalkylidenebisoxazoline compound represented by the formula (1): ##STR00003## wherein R.sup.1 represents a hydrogen atom, a C1-6 alkyl group, and so on; R.sup.2 represents a C1-6 alkyl group and so on; and n represents an integer of 0 to 3; provided that, two R.sup.1s may be bonded each other together with the carbon atom to which they are bonded to form a ring; and * represents an asymmetric carbon atom, and a copper compound, is provided.