Recurrent sequence,congruence and quadratic residue are used to prove the following conclusions.(1)Diophantine equation x2-3y4=13 has only positive integer solutions(x,y)=(4,1),(16,3);(2)Diophantine equation x2-3y4=37 has no positive integer solution;③Diophantine equation x2-3y4=61 has only positive integer solutions(x,y)=(8,1),(44,5);④Diophantine equations x2-3y4=73 has only positive integer solutions(x,y)=(11,2),(29,4).