TECHNOLOGY FOCUS - POLYMERS - Preparation (claimed): Aryl of formula: X-Ar2-X, and arylamine of formula: Ar1-NH2 are condensed in presence of palladium compound, phosphine compound and base, and further aryl is added to the mixture, and polymerized to obtain polymer (A). Then, conjugated polymer was obtained using the polymer (A).X=leaving group.Preferred Components: The insolubilization group is cross-linkable group or dissociation group. The cross-linkable group is chosen from group of formula (a-k), preferably group of formula (f). The conjugated polymer contains nitrogen-containing repeating unit of formula: -(Ar21-N(-Ar23)-(Ar24-N(-Ar25))n-Ar22)- (I'). The repeating unit of conjugated polymer is chosen from group (A) having bicyclooctatriene-containing repeating units of formulae (i-ix), and group (B) having amine-containing repeating units of formulae (x-xix).R1-R5=H or alkyl;Ar31=aromatic heterocyclic group or aromatic hydrocarbyl (both optionally having substituent), and optionally having substituent, which are optionally combined to form benzocyclobutene ring;Ar21,Ar22=Ar11;Ar23-Ar25=Ar13;andn=m.Preferred Composition: The composition further contains electron-accepting compound. The content of aryl after carrying out condensation reaction is 20-75 mol% with respect to arylamine, and 80-110 mol% after adding aryl with respect to arylamine. Preferred Element: The organic layer containing insolubilization polymer is positive hole injection layer or hole transport layer. The organic electro luminescent has positive hole injection layer, hole transport layer and light emitting layer as organic layer. The positive hole injection layer, hole transport layer and light emitting layer are formed by wet-forming method. EXAMPLE - 3-Bicyclo(4.2.0)octa-1,3,5-trien-3-yl aniline (in g) (0.9), 4-n-octylaniline (3.71), 4,4'-dibromobiphenyl (3.53), sodium tert-butoxide (6.95) and toluene (51 ml) were mixed and heated to obtain solution (A). Tri-t-butylphosphine (0.37) was added to toluene solution of tris(dibenzylidene acetone)dipalladium chloroform complex (0.23) and heated at 50 degrees C to obtain solution (B). Then, obtained solution (B) was added to solution (A) and heated for 1 hour. Then, 4,4'-dibromobiphenyl (0.07) was added to resulting mixture and reacted to obtain polymer. The obtained polymer was dissolved in toluene, and bromobenzene (0.71) and sodium tert-butoxide (3.5) were added to resulting solution and heated to obtain solution (C). Tri-t-butylphosphine (0.18) was added to toluene solution of tris(dibenzylidene acetone)dipalladium chloroform complex (0.12) and heated at 50 degrees C to obtain solution (D). Then, obtained solution (D) was added to solution (C) and heat-refluxed. Then, toluene solution of N,N-diphenylamine (3.82) was added to resulting solution and heat-refluxed to obtain polymer having weight average molecular weight of 63900 and number average molecular weight of 40300.