diff --git a/mamotif/region.py b/mamotif/region.py
new file mode 100644
index 0000000..1b16d89
--- /dev/null
+++ b/mamotif/region.py
@@ -0,0 +1,105 @@
+"""
+mamotif.region
+--------------
+Genomic regions use in MAmotif.
+"""
+
+import logging
+
+import numpy as np
+from motifscan.region import load_motifscan_regions
+
+logger = logging.getLogger(__name__)
+
+
+class MamotifRegion:
+    """Class for a MAmotif genomic region.
+
+    Parameters
+    ----------
+    chrom : str
+        The chromosome name of the region.
+    start : int
+        The start coordinate of the region.
+    end : int
+        The end coordinate of the region.
+    m_value: float, optional
+        The m_value of the region.
+    n_sites: list of int
+        The motif sites numbers of the region.
+
+    Attributes
+    ----------
+    chrom : str
+        The chromosome name of the region.
+    start : int
+        The start coordinate of the region.
+    end : int
+        The end coordinate of the region.
+    m_value : float or None
+        The m_value of the region or None if not specified.
+    has_motif : list of bool
+        The target site indicators for motifs.
+
+    Notes
+    -----
+    The coordinates are 0-based, which means the region range is [start, end).
+    """
+
+    def __init__(self, chrom, start, end, n_sites, m_value=None):
+        self.chrom = chrom
+        self.start = int(start)
+        self.end = int(end)
+        self.m_value = m_value
+        self.has_motif = np.asarray(n_sites) > 0
+
+    def match_manorm(self, manorm_regions):
+        for region in manorm_regions:
+            if (region.chrom == self.chrom) and (
+                    region.start == self.start) and (region.end == self.end):
+                self.m_value = region.score
+                break
+        if self.m_value is None:
+            raise ValueError(f"no matched MAnorm region found for: {self!r}")
+
+    def __repr__(self):
+        return f"GenomicRegion({self.chrom}:{self.start}-{self.end})"
+
+
+def load_mamotif_regions(f_manorm, f_motifscan):
+    logger.info("Loading MAnorm result")
+    manorm_regions = load_motifscan_regions(f_manorm, 'manorm')
+    logger.info("Loading MotifScan result")
+    logger.info(f"Loading genomic regions from {f_motifscan} [motifscan]")
+    regions = []
+    with open(f_motifscan, 'r') as fin:
+        line = fin.readline()
+        header = line.strip().split('\t')
+        if header[:3] != ['chr', 'start', 'end']:
+            raise ValueError(
+                "not a valid MotifScan motif_sites_number.xls file")
+        motifs = header[3:]
+        for line in fin:
+            fields = line.strip().split('\t')
+            chrom = fields[0]
+            start = int(fields[1]) - 1
+            end = int(fields[2])
+            n_sites = list(map(int, fields[3:]))
+            region = MamotifRegion(chrom=chrom, start=start, end=end,
+                                   n_sites=n_sites)
+            regions.append(region)
+    logger.info(f"Loaded {len(regions)} genomic regions")
+
+    logger.info("Matching MAnorm and MotifScan results")
+    if len(manorm_regions) != len(regions):
+        logger.warning("the number of genomic regions are unmatched!")
+    # group manorm regions by chrom to match with motifscan
+    manorm_regions_by_chrom = {}
+    for region in manorm_regions:
+        manorm_regions_by_chrom.setdefault(region.chrom, [])
+        manorm_regions_by_chrom[region.chrom].append(region)
+
+    # find the matched manorm region and set the M value
+    for region in regions:
+        region.match_manorm(manorm_regions_by_chrom[region.chrom])
+    return motifs, regions