NOVELTY - An ultrahigh-molecular-weight polyethylene powder has viscosity-average molecular weight of 1500000-10000000 and heat-of-fusion of 180-230 J/g. The maximum torque during mixing of liquid paraffin and 20-25 weight% of polyethylene powder, exists at temperature (a) of 140-160?oC. The maximum torque during mixing of liquid paraffin and 5-10 weight% of polyethylene powder, exists at temperature (b) which is more than the temperature (a).    USE - Ultrahigh-molecular-weight polyethylene powder is used for manufacture of sintered compact and molded products (claimed) used for engineering plastics. Uses include but are not limited to battery-cell separator, suction sheet, humidification element, hemodialysis filter, biological analysis kit, support component of ion exchange resin, ink absorber for printer head, support component of electrolyte, electronic components and fuel cell.    ADVANTAGE - The molded product of ultrahigh-molecular-weight polyethylene powder has excellent workability and high strength and elastic modulus.    DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for the following:    (1) manufacture of ultrahigh-molecular-weight polyethylene powder, which involves polymerizing olefin polymerization catalyst containing solid catalyst component and organometallic compound. The solid catalyst component is supported with titanium compound of formula: Ti(OR11)wZ4-w (III), and is obtained by reacting organic magnesium compound of formula: M1eMggR1pR2qXrY's which is soluble in hydrocarbon solvent, and silicon chloride compound of formula: HaSiClbR104-(a+b). The organometallic compound is triethylaluminum;    (2) sintered compact, which is obtained by heating the polyethylene powder;    (3) molded product, which is obtained by heating and rolling polyethylene powder;    (4) manufacture of sintered compact, which involves filling polyethylene powder in metal mold having predetermined shape, and heating in non-pressure state or pressurized state; and    (5) manufacture of molded product, which involves measuring solubility and fusibility of polyethylene powder by comparing temperature at maximum value of measured torque and temperature during molding polyethylene powder, mixing plasticizer, heating and rolling. When heating the polyethylene powder and plasticizer with temperature increase rate of 0.3-10?oC/minute from temperature less than melting point to more than melting point of polyethylene powder, the torque produced during mixing of plasticizer is measured.    M1=group I-III, group XII or group XIII elements;    R1,R2=2-20C hydrocarbyl;    X,Y'=OR3, OSiR4R5R6, NR7R8, SR9 or halo;    R4-R8=H or 1-20C hydrocarbyl;    e,p-s=0 or more;    (r+s)/e+g=0-2;    ke+2g=p+q+r+s;    k=valency of M1;    R3,R9,R10=1-20C hydrocarbyl;    g,p+q,a,b=more than 0;    a+b=\~4;    R11=hydrocarbyl;    Z=halo;and    w=0-4.