【Objective】How to monitor and assess soil Cd pollution and bioavailability is currently an issue of great concern. However, measurements of soil available Cd contents using the conventional chemical methods may only serve as certain reference, because they are not good enough to intuitively and truly reflect the damages soil Cd²⁺ does to plants. Bryophyta are simple in structure, free of any cuticle on their surface and quite sensitive to pollutants, so they are usually used in monitoring environmental pollution. In this paper, an effective method was preliminarily studied to monitor and evaluate soil Cd pollution and Cd bioavailability using Pogonatum inflexum, a species of bryophyte highly sensitive to soil Cd. A mature plant of the sporophytic generation of Pogonatum inflexum could be as high as 10 cm. Besides, it is simple in surface structure with no vascular bundle differentiation, but with sporophytes parasitizing on gametophytes. Furthermore, the various organs of Pogonatum inflexum are homogeneous in cell structure and mostly monolayer cells.【Method】In the experiment to validate effectiveness of the method, the tested soil was prepared into media, different in Cd contamination degree (1~5 mg kg^-1), for culture of Pogonatum inflexum. Growth, Cd enrichment, chlorophyll content, soluble protein content and MDA concentration of the bryophyte was observed and/or determined. Soil available Cd contents extracted with acetic acid were cited as indicator parameter for soil Cd bioavailability, and then analysis was done of correlations of the above described indices with content of soil total Cd and content of soil available Cd, separately.【Result】Results show that in the test soil, bioavailable Cd accounted for about 20%~40% of total Cd. All the indexes of Pogonatum inflexummentioned above were closely related to soil Cd stress, especially when soil Cd concentration was higher than 3 mg kg^-1. Pogonatum inflexum was low in Cd enrichment and in tolerance to Cd as well. It could enrich as high as Cd 1.627 mg kg^-1, with enrichment coefficient being 63.9% and Cd concentration in Pogonatum inflexum was more closely related to soil bioavailable Cd than to soil total Cd. Pogonatum inflexum responded quite apparently to soil Cd pollution, with visible symptoms such as damaged sporophytes and gametophytes. When soil Cd concentration was higher than 1~2 mg kg^-1 (available Cd concentration was higher than 0.559 mg kg^-1), leaves ofPogonatum inflexum turned yellow and brown; when soil Cd concentration got up to 5 mg kg^-1, seta softened and kinked, till the plants withered dead. Changes in physiological and biochemical indexes of the tested plants, such as contents of chlorophyll, soluble protein and MDA, were apparently related to soil Cd stress, especially to soil bioavailable Cd contents, and corresponded well to changes in soil Cd pollution level.【Conclusion】Therefore, the contents of chlorophyll, soluble protein and MDA in Pogonatum inflexum can be used as indicators to monitor and evaluate soil Cd pollution and bioavailabilty. Pogonatum inflexum is an ideal material to be used to effectively monitor soil Cd pollution thanks to its high sensitivity to soil Cd²⁺ and its readiness and intuitiveness in displaying damage symptoms.