This paper is concerned with positive
α
-times resolvent families on an ordered Banach space
E
(with normal and generating cone), where
0
<
α
≤
2
. We show that a closed and densely defined operator
A
on
E
generates a positive exponentially bounded
α
-times resolvent family for some
0
<
α
<
1
if and only if, for some
ω
∈
ℝ
, when
λ
>
ω
,
λ
∈
ρ
A
,
R
λ
,
A
≥
0
and
sup
λ
R
λ
,
A
:
λ
≥
ω
<
∞
. Moreover, we obtain that when
0
<
α
<
1
, a positive exponentially bounded
α
-times resolvent family is always analytic. While
A
generates a positive
α
-times resolvent family for some
1
<
α
≤
2
if and only if the operator
λ
α
−
1
λ
α
−
A
−
1
is completely monotonic. By using such characterizations of positivity, we investigate the positivity-preserving of positive fractional resolvent family under positive perturbations. Some examples of positive solutions to fractional differential equations are presented to illustrate our results.