This　paper　is　concerned　with　the　Riemann　problem　for　the　isentropic　Chaplygin　gas　magnetogasdynamics　equations　and　the　formation　of　delta-shocks　and　vacuum　states　as　pressure　and　magnetic　field　vanish.　Firstly,　the　Riemann　problem　of　the　isentropic　magnetogasdynamics　equations　for　Chaplygin　gas　is　solved　analytically.　Secondly,　it　is　rigorously　proved　that,　as　both　the　pressure　and　the　magnetic　field　vanish,　the　Riemann　solution　containing　two　shocks　tends　to　a　delta-shock　solution　to　the　transport　equations,　and　the　intermediate　density　between　the　two　shocks　tends　to　a　weighted　delta-measure　which　form　the　delta-shock;　while　the　Riemann　solution　containing　two　rarefaction　waves　tends　to　a　two-contact-discontinuity　solution　to　the　transport　equations　if　we　do　not　consider　the　virtual　velocity　in　the　vacuum　region,　the　intermediate　state　between　the　two　contact　discontinuities　is　a　vacuum　state.　Moreover,　we　also　give　some　numerical　simulations　to　confirm　the　theoretical　analysis.