diff --git a/message_ix/tests/tools/test_lpdiag.py b/message_ix/tests/tools/test_lpdiag.py
new file mode 100644
index 000000000..4a344b9da
--- /dev/null
+++ b/message_ix/tests/tools/test_lpdiag.py
@@ -0,0 +1,151 @@
+import os
+
+from message_ix.tools.lp_diag.lp_diag import LPdiag
+
+file = os.path.join(os.getcwd(), "message_ix", "tools", "lp_diag", "test_mps", "lotfi")
+lp = LPdiag()
+lp.rd_mps(file)  # read MPS, store the matrix in dataFrame
+lp.mps_sum()
+
+lp.mat.shape
+lp.n_lines
+len(lp.row_name)
+len(lp.col_name)
+dens = f"{float(len(lp.mat)) / (len(lp.row_name) * len(lp.col_name)):.2e}"
+dens
+
+
+def test_aez():
+    """Test reading of aez.mps file
+
+    Check that the number of lines, rows and columns are correct"""
+
+    # Read in the default MPS file for testing (aez.mps in test_mps folder)
+    file = os.path.join(
+        os.getcwd(), "message_ix", "tools", "lp_diag", "test_mps", "aez"
+    )
+    lp = LPdiag()
+
+    # Read MPS, store the matrix in dataFrame
+    lp.rd_mps(file)
+
+    # Check that the matrix has the correct shape
+    assert lp.mat.shape == (8895, 5)
+
+    # Check that the number of lines is correct
+    assert lp.n_lines == 5528
+
+    # Check that the number of rows is correct
+    assert len(lp.row_name) == 329
+
+    # Check that the number of columns is correct
+    assert len(lp.col_name) == 637
+
+    # Check matrix density
+    dens = f"{float(len(lp.mat)) / (len(lp.row_name) * len(lp.col_name)):.2e}"
+    assert dens == "4.24e-02"
+
+    # Check that sequence number of the goal function is not -1
+    assert lp.gf_seq != -1
+
+
+def test_diet():
+    """Test reading of diet.mps file
+
+    Check that the number of lines, rows and columns are correct"""
+
+    # Read in the diet.mps file
+    file = os.path.join(
+        os.getcwd(), "message_ix", "tools", "lp_diag", "test_mps", "diet"
+    )
+    lp = LPdiag()
+
+    # Read MPS, store the matrix in dataFrame
+    lp.rd_mps(file)
+
+    # Check that the matrix has the correct shape
+    assert lp.mat.shape == (39, 5)
+
+    # Check that the number of lines is correct
+    assert lp.n_lines == 66
+
+    # Check that the number of rows is correct
+    assert len(lp.row_name) == 5
+
+    # Check that the number of columns is correct
+    assert len(lp.col_name) == 8
+
+    # Check matrix density
+    dens = f"{float(len(lp.mat)) / (len(lp.row_name) * len(lp.col_name)):.2e}"
+    assert dens == "9.75e-01"
+
+    # Check that sequence number of the goal function is not -1
+    assert lp.gf_seq != -1
+
+
+def test_jg_korh():
+    """Test reading of jg_korh.mps file
+
+    Check that the number of lines, rows and columns are correct"""
+
+    # Read in the diet.mps file
+    file = os.path.join(
+        os.getcwd(), "message_ix", "tools", "lp_diag", "test_mps", "jg_korh"
+    )
+    lp = LPdiag()
+
+    # Read MPS, store the matrix in dataFrame
+    lp.rd_mps(file)
+
+    # Check that the matrix has the correct shape
+    assert lp.mat.shape == (10, 5)
+
+    # Check that the number of lines is correct
+    assert lp.n_lines == 21
+
+    # Check that the number of rows is correct
+    assert len(lp.row_name) == 4
+
+    # Check that the number of columns is correct
+    assert len(lp.col_name) == 3
+
+    # Check matrix density
+    dens = f"{float(len(lp.mat)) / (len(lp.row_name) * len(lp.col_name)):.2e}"
+    assert dens == "8.33e-01"
+
+    # Check that sequence number of the goal function is not -1
+    assert lp.gf_seq != -1
+
+
+def test_lotfi():
+    """Test reading of lotfi.mps file
+
+    Check that the number of lines, rows and columns are correct"""
+
+    # Read in the diet.mps file
+    file = os.path.join(
+        os.getcwd(), "message_ix", "tools", "lp_diag", "test_mps", "lotfi"
+    )
+    lp = LPdiag()
+
+    # Read MPS, store the matrix in dataFrame
+    lp.rd_mps(file)
+
+    # Check that the matrix has the correct shape
+    assert lp.mat.shape == (1086, 5)
+
+    # Check that the number of lines is correct
+    assert lp.n_lines == 785
+
+    # Check that the number of rows is correct
+    assert len(lp.row_name) == 154
+
+    # Check that the number of columns is correct
+    assert len(lp.col_name) == 308
+
+    # Check matrix density
+    dens = f"{float(len(lp.mat)) / (len(lp.row_name) * len(lp.col_name)):.2e}"
+    assert dens == "2.29e-02"
+
+    # Check that sequence number of the goal function is not -1
+    assert lp.gf_seq != -1