diff --git a/ecell4/sgfrd/SGFRDWorld.cpp b/ecell4/sgfrd/SGFRDWorld.cpp
index e016a719e..4a40b0510 100644
--- a/ecell4/sgfrd/SGFRDWorld.cpp
+++ b/ecell4/sgfrd/SGFRDWorld.cpp
@@ -45,16 +45,13 @@ SGFRDWorld::new_particle(const Particle& p, const FaceID& fid)
 }
 
 std::pair<std::pair<ParticleID, Particle>, bool>
-SGFRDWorld::throw_in_particle(const Species& sp_)
+SGFRDWorld::throw_in_particle(const Species& sp)
 {
-    const auto model = this->lock_model();
-    const auto sp = model->apply_species_attributes(sp_);
-    const Real r = sp.get_attribute_as<Real>("radius");
-    const Real D = sp.get_attribute_as<Real>("D");
+    const auto info = this->get_molecule_info(sp);
 
     Real3 pos; FaceID fid;
     pos = this->polygon_->draw_position(this->rng_, fid);
-    const Particle p(sp, pos, r, D);
+    const Particle p(sp, pos, info.radius, info.D);
     return this->new_particle(p, fid);
 }
 
@@ -74,7 +71,7 @@ void SGFRDWorld::add_molecules(const Species& sp, const Integer& num)
     return;
 }
 
-void SGFRDWorld::add_molecules(const Species& sp_, const Integer& num,
+void SGFRDWorld::add_molecules(const Species& sp, const Integer& num,
                                const boost::shared_ptr<Shape> shape)
 {
     if (num < 0)
@@ -163,10 +160,7 @@ void SGFRDWorld::add_molecules(const Species& sp_, const Integer& num,
         throw std::invalid_argument("The shape does not overlap with polygon.");
     }
 
-    const auto model = this->lock_model();
-    const auto sp = model->apply_species_attributes(sp_);
-    const Real r = sp.get_attribute_as<Real>("radius");
-    const Real D = sp.get_attribute_as<Real>("D");
+    const auto info = this->get_molecule_info(sp);
     for(Integer i=0; i<num; ++i)
     {
         bool particle_inserted = false;
@@ -181,7 +175,7 @@ void SGFRDWorld::add_molecules(const Species& sp_, const Integer& num,
 
             if(shape->is_inside(pos))
             {
-                const Particle p(sp, pos, r, D);
+                const Particle p(sp, pos, info.radius, info.D);
                 std::tie(std::ignore, particle_inserted) =
                     this->new_particle(p, face_id);
             }
diff --git a/ecell4/sgfrd/SGFRDWorld.hpp b/ecell4/sgfrd/SGFRDWorld.hpp
index eca714af8..4463b9766 100644
--- a/ecell4/sgfrd/SGFRDWorld.hpp
+++ b/ecell4/sgfrd/SGFRDWorld.hpp
@@ -24,6 +24,12 @@ namespace ecell4
 namespace sgfrd
 {
 
+struct MoleculeInfo
+{
+    const Real radius;
+    const Real D;
+};
+
 class SGFRDWorld
     : public ecell4::WorldInterface
 {
@@ -34,6 +40,7 @@ class SGFRDWorld
     typedef polygon_type::VertexID VertexID;
     typedef Barycentric barycentric_type;
 
+    typedef ecell4::sgfrd::MoleculeInfo molecule_info_type;
     typedef ecell4::Model model_type;
 
     typedef ParticleSpaceCellListImpl default_particle_space_type;
@@ -208,6 +215,50 @@ class SGFRDWorld
 #endif
     }
 
+    /**
+     * draw attributes of species and return it as a molecule info.
+     * @param sp a species
+     * @return info a molecule info
+     */
+    MoleculeInfo get_molecule_info(const Species& sp) const
+    {
+        Real radius(0.0), D(0.0);
+
+        if (boost::shared_ptr<Model> bound_model = lock_model())
+        {
+            auto const sp_ = bound_model->apply_species_attributes(sp);
+            if (sp_.has_attribute("radius"))
+            {
+                radius = sp_.get_attribute_as<Real>("radius");
+            }
+            if (sp_.has_attribute("D"))
+            {
+                D = sp_.get_attribute_as<Real>("D");
+            }
+        }
+
+        {
+            if (sp.has_attribute("radius"))
+            {
+                radius = sp.get_attribute_as<Real>("radius");
+            }
+            if (sp.has_attribute("D"))
+            {
+                D = sp.get_attribute_as<Real>("D");
+            }
+        }
+
+        if (radius <= 0.0)
+        {
+            std::stringstream msg;
+            msg << "A particle with invalid size [" << radius << "] was given.";
+            throw IllegalArgument(msg.str());
+        }
+
+        MoleculeInfo info = {radius, D};
+        return info;
+    }
+
     const Real volume() const override
     {
         return ps_->volume();
@@ -341,26 +392,20 @@ class SGFRDWorld
     new_particle(const Particle& p, const FaceID& fid);
 
     std::pair<std::pair<ParticleID, Particle>, bool>
-    new_particle(const Species& sp_, const Real3& pos)
+    new_particle(const Species& sp, const Real3& pos)
     {
-        const auto model = this->lock_model();
-        const auto sp = model->apply_species_attributes(sp_);
-        const Real r = sp.get_attribute_as<Real>("radius");
-        const Real D = sp.get_attribute_as<Real>("D");
-        return this->new_particle(Particle(sp, pos, r, D));
+        const auto info = this->get_molecule_info(sp);
+        return this->new_particle(Particle(sp, pos, info.radius, info.D));
     }
     std::pair<std::pair<ParticleID, Particle>, bool>
-    new_particle(const Species& sp_, const FaceID& fid, const Barycentric& bary)
+    new_particle(const Species& sp, const FaceID& fid, const Barycentric& bary)
     {
-        const auto model = this->lock_model();
-        const auto sp = model->apply_species_attributes(sp_);
-        const auto r = sp.get_attribute_as<Real>("radius");
-        const auto D = sp.get_attribute_as<Real>("D");
+        const auto info = this->get_molecule_info(sp);
 
         const auto& tri = this->polygon_->triangle_at(fid);
         const auto  pos = to_absolute(bary, tri);
 
-        return this->new_particle(Particle(sp, pos, r, D), fid);
+        return this->new_particle(Particle(sp, pos, info.radius, info.D), fid);
     }
     std::pair<std::pair<ParticleID, Particle>, bool>
     new_particle(const Species& sp, const std::pair<FaceID, Barycentric>& sfp)