diff --git a/tests/image_deconvolution/test_prior_base.py b/tests/image_deconvolution/test_prior_base.py
new file mode 100644
index 00000000..60a08aa9
--- /dev/null
+++ b/tests/image_deconvolution/test_prior_base.py
@@ -0,0 +1,29 @@
+import pytest
+import numpy as np
+
+from cosipy.image_deconvolution.prior_base import PriorBase
+
+def test_PriorBase():
+    PriorBase.__abstractmethods__ = set()
+    
+    # no class is allowered
+    with pytest.raises(TypeError) as e_info:
+        coefficient = 10
+        test_model = np.zeros(2)
+        prior = PriorBase(coefficient, test_model)
+    
+    # As a test, np.ndarray is added
+    PriorBase.usable_model_classes.append(np.ndarray)
+
+    coefficient = 10
+    test_model = np.zeros(2)
+    prior = PriorBase(coefficient, test_model)
+    
+    # other function tests
+    with pytest.raises(RuntimeError) as e_info:
+        prior.log_prior(test_model)
+    assert e_info.type is NotImplementedError
+
+    with pytest.raises(RuntimeError) as e_info:
+        prior.grad_log_prior(test_model)
+    assert e_info.type is NotImplementedError
diff --git a/tests/image_deconvolution/test_priors.py b/tests/image_deconvolution/test_priors.py
new file mode 100644
index 00000000..2aa10ee7
--- /dev/null
+++ b/tests/image_deconvolution/test_priors.py
@@ -0,0 +1,36 @@
+import pytest
+
+import astropy.units as u
+import numpy as np
+import healpy as hp
+
+from cosipy.image_deconvolution.prior_tsv import PriorTSV
+from cosipy.image_deconvolution import AllSkyImageModel
+
+def test_PriorTSV():
+
+    coefficient = 1.0
+    
+    nside = 1
+    allskyimage_model = AllSkyImageModel(nside = nside, 
+                                         energy_edges = np.array([500.0, 510.0]) * u.keV)
+    allskyimage_model[:,0] = np.arange(hp.nside2npix(nside)) * allskyimage_model.unit
+
+    prior_tsv = PriorTSV(coefficient, allskyimage_model)
+    
+    assert np.isclose(prior_tsv.log_prior(allskyimage_model), -1176.0)
+
+    grad_log_prior_correct = np.array([[  92.],
+                                       [  76.],
+                                       [  60.],
+                                       [  28.],
+                                       [  40.],
+                                       [  -8.],
+                                       [  -8.],
+                                       [ -24.],
+                                       [ -36.],
+                                       [ -52.],
+                                       [ -68.],
+                                       [-100.]]) * u.Unit('cm2 s sr')
+
+    assert np.allclose(prior_tsv.grad_log_prior(allskyimage_model), grad_log_prior_correct)