Dear hanhphuc. Thanks you for your time. This issue is not important. Don't need to spend any more time .(defun Spline:Box (obj / cpts vec p1 p2 p4 p3 lst xdir ydir) (setq cpts (mapcar 'cdr (vl-remove-if-not '(lambda (x) (= (car x) 10)) (entget obj)) ) p1 (apply 'mapcar (cons 'min cpts)) p3 (apply 'mapcar (cons 'max cpts)) ) (if (zerop (getvar "worlducs")) (setq vec (mapcar '- p3 p1) p2 (mapcar '+ p1 (list (car vec) 0.0 0.0)) p4 (mapcar '+ p1 (list 0.0 (cadr vec) 0.0)) lst (list (trans p1 0 1) (trans p2 0 1) (trans p3 0 1) (trans p4 0 1) ) p1 (trans (apply 'mapcar (cons 'min lst)) 1 0) p3 (trans (apply 'mapcar (cons 'max lst)) 1 0) xdir (getvar "ucsxdir") ydir (getvar "ucsydir") ) (setq xdir '(1.0 0.0 0.0) ydir '(0.0 1.0 0.0) ) ) (setq lst (mapcar '(lambda (a b) (vlax-curve-getClosestPointToProjection obj a b t) ) (list p1 p1 p3 p3) (list xdir ydir xdir ydir) ) ) (if (zerop (getvar "worlducs")) (setq lst (mapcar '(lambda (x) (trans x 0 1)) lst)) ) (setq p1 (apply 'mapcar (cons 'min lst)) p3 (apply 'mapcar (cons 'max lst)) ) (mapcar '(lambda (x) (trans x 1 0)) (list p1 (list (car p1) (cadr p3) (caddr p1)) p3 (list (car p3) (cadr p1) (caddr p1)) ) )) 
