The present invention provides a solid catalyst component for the
polymerization of olefins, comprising magnesium, titanium, a halogen and
an electron donor, wherein said electron donor comprises at least one
selected from the group consisting of ester of polyol of the formula (I):
R.sub.1CO--O--CR.sub.3R.sub.4--A--CR.sub.5R.sub.6--O--CO--R.sub.2 (I)
wherein, R.sub.1 and R.sub.2 groups, which may be identical or different,
can be substituted or unsubstituted hydrocarbyl having 1 to 20 carbon
atoms, R.sub.3-R.sub.6 groups, which may be identical or different, can
be selected from the group consisting of hydrogen, halogen or substituted
or unsubstituted hydrocarbyl having 1 to 20 carbon atoms, R.sub.1-R.sub.6
groups optionally contain one or more hetero-atoms replacing carbon,
hydrogen atom or the both, said hetero-atom is selected from the group
consisting of nitrogen, oxygen, sulfur, silicon, phosphorus and halogen
atom, two or more of R.sub.3-R.sub.6 groups can be linked to form
saturated or unsaturated monocyclic or polycyclic ring A is a single bond
or bivalent linking group with chain length between two free radicals
being 1-10 atoms, wherein said bivalent linking group is selected from
the group consisting of aliphatic, alicyclic and aromatic bivalent
radicals, and can carry C.sub.1-C.sub.20 linear or branched substituents
one or more of carbon atom and/or hydrogen atom on above-mentioned
bivalent linking group and substituents can be replaced by a hetero-atom
selected from the group consisting of nitrogen, oxygen, sulfur, silicon,
phosphorus, and halogen atom, and two or more said substituents on the
linking group as well as above-mentioned R.sub.3-R.sub.6 groups can be
linked to form saturated or unsaturated monocyclic or polycyclic ring.