A series of tetrapolyamides were synthesized by low temperature solution polycondensatian of terephthaloyl dichloride with 1

2-dihydro-2-(4-aminophenyl)-4-[4-(4-aminophenonxyl)phenyl]-phthalazin-1-one (DHPZ-DA)

4

4’-methylanedianiline(MDA)and p-phenylene diamine(PPD)．The synthesized polyamides were charaeterized by FHR and 1H-NMR．The polymers exhibitedinherent viscosities of l．24～2．32 dL／g and some were soluble in several organic solvents such as N-methyl pyrrolidone

N

N—dimethylacetamide and N

N— dimethylformamide．when the three kinds of diamines were in proper ratios．These polymers had glass transition temperatures above 301℃ and 5％ weight loss above 438℃ in nitrogen．Some polyamide films were prepared from their NMP solutions and had tensile strength of 64～72 MPa

elongation at break of 4．9％-8．1％ and tensile modulus of 1．7～2．1 GPa．The results showed that these polyamides showed the combination of excellent thermal properties

solubility and mechanical properties．