High speed mobile and wireless networks are expected to support multimedia traffic with different quality of service (QoS). However the high mobility of users, channel fading effect and limited bandwidth make QoS provision a challenging issue. In this paper, we classify multimedia traffic into three classes: CBR real-time traffic, VBR real-time traffic and VBR non real-time traffic. We propose a weight-based adaptive call admission control scheme in mobile wireless multimedia networks. The basic strategy is to look at the actual demand of bandwidth determined by both arrival rate and required transmission rate for each class of traffic. Our weight-based adaptive call admission control scheme is observed to maintain a good QoS through extensive simulations.