TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Agent: The crosslinking agent is chosen from an isocyanate compound, an epoxy compound, an aldehyde-type compound, chlorosilane, alkoxysilane, a melamine-type compound, a sulfur or sulfur compound, hydrosilane, peroxide, and azo compound, preferably silane compound of formula: R06-Si(-R06)(-R06)-R06.R06=H, 1-6C linear or branched alkyl, 2-7C alkenyl, or 6-8C aryl.    TECHNOLOGY FOCUS - POLYMERS - Preferred Compound: The polysiloxane compound further contains condensation unit of formula: (Si(-R024-q)-Oq)- (II). The terminal of polysiloxane structure is blocked by silicon-containing group of formula: R03-Si(-R03)(-R03)-.R02,R03=H, alkyl, alkenyl or aryl;andq=1-4.The polysiloxane compound includes 2-150 condensation units (I) and 0-150 condensation units (II). The polysiloxane compound has hydroxyl group, mercapto group, carboxyl group, amino group, epoxy group, alkenyl group, alkynyl group, acryloyl group, methacryloyl group, chlorosilyl group, alkoxysilyl group and/or hydrosilyl group as a crosslinkable group. The amount of condensation unit (I) is 5 %mass or more. Preferred Composition: The polysiloxane composition further contains siloxane compound of formula: R05-Si(-R05)(-R05)-O-(Si(-R04)(-R04)-O)z-Si(-R05)(-R05)-R05.R04,R05=H, alkyl, alkenyl or aryl;andz=0-150. Preferred Definitions:    W'=single bond, 1-10C linear or branched alkylene, or bivalent organic group: -(CH2)n-A-(CH2)n-;    m=2-5;    n=0-5;    A=-S(=O)(=O)-, -C(=O)-, -O-CH2-CH(-OH)-, -O-CH2-CH(-NH2)-, or -O-;and    R01,R07=1-6C alkoxy, 1-6C linear or branched, 2-6C alkenyl or 6-8C aryl.    EXAMPLE - 4,4-Bis(trifluoromethanesulfonyl)butyl dichloromethylsilane (in g) (28.1), dimethylvinyl chlorosilane (5.9), and tetrahydrofuran (10.8) were added to flask and cooled. Ion-exchange water (5) was dropped, stirred and mixed at room temperature. The reaction solution was diluted with isopropyl ether, organic layer was washed with water and solvent was distilled off. The product was heated and vacuum-dried to obtain polysiloxane compound of formula (a) (23.3) in the form of pale yellow liquid.