The existence of Islamic Bank in Indonesia is regulated by Law No. 10 of 1998 which had a chance banking operations with the operational basis for the results. The emergence of the operational legal basis of Islamic banks in Indonesia, marking the start of the era of dual banking system. The research raises two issues, namely how the mechanism of credit agreement with a guarantee that uses Mortgage Notary in Bank Muamalat and how the role of the Notary in the loan agreement with collateral Mortgage in Bank Muamalat. The author uses the method of normative analysis shows that the operational rules that form the basis of Islamic banks in the form of legislation is Act No. 7 of 1992 in conjunction with Act No. 10 of 1998, the data collection is done by the method of approach to legislation. Notary makes deed of Credit Agreement with Bank Muamalat based on economic principles are based on Islamic law that refers to the Islamic economic relations commercial contract, which is the legal construction is based on the sale and purchase agreement (Ba'iu), unions (Syirkah), deposits (Al Wadi'ah ), rent (Al Ijaroh), granting bail (Al Kafalah). Specialized in the credit agreement known Financing virtue (Qordhul Hasan). Financing agreement based on the principle of sharing is one type of financing that is born of a partnership contract relationship (Syirkah). / Keberadaan Bank Syariah di Indonesia diatur dalam Undang-Undang Nomor 10 Tahun 1998 yang memiliki peluang kegiatan usaha perbankan dengan dasar operasional bagi hasil. Kemunculan dasar hukum operasional bank syariah di Indonesia ini, menandai dimulainya era sistem perbankan ganda. Penelitian ini mengangkat dua permasalahan yaitu bagaimanakah mekanisme perjanjian kredit dengan jaminan Hak Tanggungan yang menggunakan Notaris di Bank Muamalat dan bagaimanakah peran Notaris dalam perjanjian kredit dengan jaminan Hak Tanggungan di Bank Muamalat. Penulis menggunakan metode analisis normatif yang memperlihatkan bahwa peraturan yang menjadi landasan operasional bank syariah berbentuk Undang-undang adalah Undang-Undang Nomor 7 Tahun 1992 jo Undang-Undang Nomor 10 Tahun 1998, pengumpulan data dilakukan dengan metode pendekatan perundang-undangan. Notaris membuat akta Perjanjian Kredit di Bank Muamalat berdasarkan prinsip-prinsip ekonomi yang berlandaskan syariah Islam yang mengacu pada hubungan akad perniagaan ekonomi Islam, yaitu konstruksi hukum berdasarkan akad jual beli (Ba'iu), perserikatan (Syirkah ), titipan (Al Wadi'ah ), sewa (Al Ijaroh), Pemberian jaminan (Al Kafalah). Khusus dalam perjanjian kredit dikenal Pembiayaan kebajikan (Qordhul Hasan). Perjanjian pembiayaan berdasarkan prinsip bagi hasil merupakan salah satu jenis pembiayaan yang lahir dari hubungan akad persekutuan (Syirkah).