diff --git a/common/countdown/countdown.go b/common/countdown/countdown.go
index e914fa8da908..1f753a659ac6 100644
--- a/common/countdown/countdown.go
+++ b/common/countdown/countdown.go
@@ -23,12 +23,21 @@ type CountdownTimer struct {
 	OnTimeoutFn func(time time.Time, i ...interface{}) error
 }
 
-func NewCountDown(duration time.Duration) *CountdownTimer {
+func NewConstCountDown(duration time.Duration) *CountdownTimer {
 	return &CountdownTimer{
 		resetc:         make(chan int),
 		quitc:          make(chan chan struct{}),
 		initilised:     false,
-		durationHelper: NewConstTimeoutDuration(duration), //TODO: change to NewExpTimeoutDuration
+		durationHelper: NewConstTimeoutDuration(duration),
+	}
+}
+
+func NewExpCountDown(duration time.Duration, base float64, max_exponent uint8) *CountdownTimer {
+	return &CountdownTimer{
+		resetc:         make(chan int),
+		quitc:          make(chan chan struct{}),
+		initilised:     false,
+		durationHelper: NewExpTimeoutDuration(duration, base, max_exponent),
 	}
 }
 
diff --git a/common/countdown/countdown_test.go b/common/countdown/countdown_test.go
index 382ace22bac0..9112133f026e 100644
--- a/common/countdown/countdown_test.go
+++ b/common/countdown/countdown_test.go
@@ -16,7 +16,7 @@ func TestCountdownWillCallback(t *testing.T) {
 		return nil
 	}
 
-	countdown := NewCountDown(1000 * time.Millisecond)
+	countdown := NewConstCountDown(1000 * time.Millisecond)
 	countdown.OnTimeoutFn = OnTimeoutFn
 	countdown.Reset(fakeI)
 	<-called
@@ -31,7 +31,7 @@ func TestCountdownShouldReset(t *testing.T) {
 		return nil
 	}
 
-	countdown := NewCountDown(5000 * time.Millisecond)
+	countdown := NewConstCountDown(5000 * time.Millisecond)
 	countdown.OnTimeoutFn = OnTimeoutFn
 	// Check countdown did not start
 	assert.False(t, countdown.isInitilised())
@@ -79,7 +79,7 @@ func TestCountdownShouldResetEvenIfErrored(t *testing.T) {
 		return errors.New("ERROR!")
 	}
 
-	countdown := NewCountDown(5000 * time.Millisecond)
+	countdown := NewConstCountDown(5000 * time.Millisecond)
 	countdown.OnTimeoutFn = OnTimeoutFn
 	// Check countdown did not start
 	assert.False(t, countdown.isInitilised())
@@ -127,7 +127,7 @@ func TestCountdownShouldBeAbleToStop(t *testing.T) {
 		return nil
 	}
 
-	countdown := NewCountDown(5000 * time.Millisecond)
+	countdown := NewConstCountDown(5000 * time.Millisecond)
 	countdown.OnTimeoutFn = OnTimeoutFn
 	// Check countdown did not start
 	assert.False(t, countdown.isInitilised())
@@ -144,7 +144,7 @@ func TestCountdownShouldBeAbleToStop(t *testing.T) {
 func TestCountdownShouldAvoidDeadlock(t *testing.T) {
 	var fakeI interface{}
 	called := make(chan int)
-	countdown := NewCountDown(5000 * time.Millisecond)
+	countdown := NewConstCountDown(5000 * time.Millisecond)
 	OnTimeoutFn := func(time.Time, ...interface{}) error {
 		countdown.Reset(fakeI)
 		called <- 1
diff --git a/common/countdown/exp_duration_test.go b/common/countdown/exp_duration_test.go
index cfd5a4d283e5..2f2363ea2f95 100644
--- a/common/countdown/exp_duration_test.go
+++ b/common/countdown/exp_duration_test.go
@@ -50,6 +50,11 @@ func TestExpDuration(t *testing.T) {
 	currentRound++
 	result = helper.GetTimeoutDuration(nil, currentRound, highestQCRound)
 	assert.Equal(t, duration*time.Duration(base)*time.Duration(base)*time.Duration(base), result)
+
+	// extreme case
+	helper.SetParams(duration, float64(0), uint8(0))
+	result = helper.GetTimeoutDuration(nil, currentRound, highestQCRound)
+	assert.Equal(t, duration, result)
 }
 
 func TestInvalidParameter(t *testing.T) {
diff --git a/consensus/XDPoS/engines/engine_v2/engine.go b/consensus/XDPoS/engines/engine_v2/engine.go
index 3462cce54603..5b33756cb8ed 100644
--- a/consensus/XDPoS/engines/engine_v2/engine.go
+++ b/consensus/XDPoS/engines/engine_v2/engine.go
@@ -75,7 +75,7 @@ func New(chainConfig *params.ChainConfig, db ethdb.Database, minePeriodCh chan i
 	config := chainConfig.XDPoS
 	// Setup timeoutTimer
 	duration := time.Duration(config.V2.CurrentConfig.TimeoutPeriod) * time.Second
-	timeoutTimer := countdown.NewCountDown(duration)
+	timeoutTimer := countdown.NewExpCountDown(duration, config.V2.CurrentConfig.ExpTimeoutConfig.Base, config.V2.CurrentConfig.ExpTimeoutConfig.MaxExponent)
 
 	snapshots, _ := lru.NewARC(utils.InmemorySnapshots)
 	signatures, _ := lru.NewARC(utils.InmemorySnapshots)
@@ -143,7 +143,7 @@ func (x *XDPoS_v2) UpdateParams(header *types.Header) {
 
 	// Setup timeoutTimer
 	duration := time.Duration(x.config.V2.CurrentConfig.TimeoutPeriod) * time.Second
-	x.timeoutWorker.SetParams(duration)
+	x.timeoutWorker.SetParams(duration, x.config.V2.CurrentConfig.ExpTimeoutConfig.Base, x.config.V2.CurrentConfig.ExpTimeoutConfig.MaxExponent)
 
 	// avoid deadlock
 	go func() {
diff --git a/params/config.go b/params/config.go
index a97f07bfb336..ceacc3b1e87e 100644
--- a/params/config.go
+++ b/params/config.go
@@ -466,6 +466,13 @@ type V2Config struct {
 	TimeoutSyncThreshold int     `json:"timeoutSyncThreshold"` // send syncInfo after number of timeout
 	TimeoutPeriod        int     `json:"timeoutPeriod"`        // Duration in ms
 	CertThreshold        float64 `json:"certificateThreshold"` // Necessary number of messages from master nodes to form a certificate
+
+	ExpTimeoutConfig ExpTimeoutConfig `json:"expTimeoutConfig"`
+}
+
+type ExpTimeoutConfig struct {
+	Base        float64 `json:"base"`        // base in base^exponent
+	MaxExponent uint8   `json:"maxExponent"` // max exponent in base^exponent
 }
 
 func (c *XDPoSConfig) String() string {